Automated instrument preload engage/disengage mechanism

ABSTRACT

Techniques for automated engagement and disengagement of a preload include a computer-assisted apparatus. The computer-assisted apparatus includes an instrument manipulator assembly including a preload assembly and a controller coupled to the instrument manipulator assembly. The controller is configured to move the instrument manipulator assembly to a fully withdrawn position and command the preload assembly to engage a preload. In some embodiments, engaging the preload causes the preload assembly to assert a preload force on a motor pack of the instrument manipulator assembly. In some embodiments, the controller is further configured to move the instrument manipulator assembly to a home position after the preload is engaged.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 16/317,484, filed on Jan. 11, 2019, which is a U.S. NationalStage patent application of International Patent Application No.PCT/US2017/038455, filed on Jun. 21, 2017, the benefit of which isclaimed, and claims priority to and the benefit of the filing date ofU.S. Provisional Patent Application No. 62/362,176, entitled “AUTOMATEDINSTRUMENT PRELOAD ENGAGE/DISENGAGE MECHANISM” filed Jul. 14, 2016, eachof which is incorporated by reference herein in its entirety.

BACKGROUND Field of the Invention

The present invention relates generally to teleoperated instruments andsystems, and more particularly to teleoperated instruments and systemsthat utilize preload forces.

Description of Related Art

Robotically controlled systems such as employed for minimally invasivemedical procedures can include large and complex equipment to preciselycontrol and drive relatively small tools or instruments. (As usedherein, the terms “robot” or “robotically” and the like includeteleoperation or telerobotic aspects.) FIG. 1A illustrates an example ofa known robotically controlled system 100. System 100, which may, forexample, be part of a da Vinci® Surgical System commercialized byIntuitive Surgical, Inc., includes a patient-side system 110 havingmultiple arms 130. Each arm 130 has a docking port with a drive system140 that generally includes a drive system with a mechanical interfacefor mounting and providing mechanical power for operation of aninstrument 150. Arms 130 can be used during a medical procedure to moveand position respective instruments 150 for the procedure.

FIG. 1B shows a bottom view of a known instrument 150. Instrument 150generally includes a transmission or backend mechanism 152, a main tube154 extending from the backend mechanism 152, and a functional tip 156at the distal end of the main tube 154. Tip 156 generally includes amedical tool such as a scalpel, scissors, forceps, or a cauterizinginstrument that can be used during a medical procedure. Drive cables ortendons 155 are connected to tip 156 and extend through main tube 154 tobackend mechanism 152. Backend mechanism 152 typically provides amechanical coupling between drive tendons 155 of the instrument 150 andmotorized axes of the mechanical interface of a drive system 140. Inparticular, gears or disks 153 have features such as projections orholes that are positioned, sized, and shaped to engage complementaryfeatures on the mechanical interface of a drive system 140. In a typicalinstrument, rotation of disks 153 pulls on respective drive tendons 155and actuates corresponding mechanical links in tip 156. System 100 canthus control movement and tension in drive tendons 155 as needed toposition, orient, and operate tip 156. Further details of known surgicalsystems are described, for example, in U.S. Pat. No. 7,048,745 (filedAug. 13, 2001) to Tierney et al., entitled “Surgical Robotic Tools, DataArchitecture, and Use,” which is hereby incorporated by reference in itsentirety.

Instruments 150 of system 100 can be interchanged by removing oneinstrument 150 from a drive system 140 and then installing anotherinstrument 150 in place of the instrument removed. The installationprocess in general requires that the features on disks 153 properlyengage complementary features of drive system 140. However, beforeinstallation, the orientations of disks 153 on instrument 150 aregenerally unknown to patient-side system 110.

Further, equipment such as patient-side system 110 is often covered fora medical procedure by a sterile barrier (e.g., a plastic sheet drape)because of the difficulty in cleaning and sterilizing complex equipmentbetween medical procedures. This sterile barrier can include a sterileadaptor that is interposed between the docking port associated withdrive system 140 and instrument's backend mechanism 152. See forexample, U.S. Pat. Nos. 7,048,745 and 7,699,855 (filed Mar. 31, 2006) toAnderson et al., entitled “Sterile Surgical Adaptor”, each of which isincorporated herein by reference in its entirety, and which describesome exemplary sterile barrier and adaptor systems.

A typical installation process for an instrument 150 involves mountingbackend mechanism 152 without regard for the orientations of disks 153on a drive system 140, possibly with an intervening sterile adaptor. Thedrive motors in drive system 140 may be then be rotated back and forthmultiple times during the installation procedure to ensure that thecomplementary features mesh with and securely engage each other foroperation of the newly installed instrument 150. At some point duringthe installation process, the drive motors become securely engaged torotate respective disks 153. However, the instrument 150 being installedmay move in an unpredictable manner at times during the installationprocedure because the drive motors positively engage respective disks153 of instrument 150 at different and unpredictable times. For certainapplications, such unpredictable motion is unacceptable. In general,clear or confined space is required around an instrument 150 toaccommodate random movements of the instrument tip during aninstallation procedure.

SUMMARY

A computer-assisted surgical apparatus includes a preload assembly and acontroller. The controller is coupled to the preload assembly. Thepreload assembly includes a preload engage/disengage mechanism. Thecontroller is configured to move the preload assembly until the preloadassembly is fully withdrawn; to activate the preload engage/disengagemechanism if the preload assembly is fully withdrawn; and to move thepreload assembly to a home position after activating the preloadengage/disengage mechanism.

The apparatus also includes a surgical instrument manipulator assemblythat includes the preload assembly, a housing, and a motor pack movablymounted in the housing. The preload assembly includes a cam followingassembly that includes a wheel and a body. The wheel is configured toride on a preload track. The body of the cam following assembly isrotatably coupled to a first pivot pin. The body includes a first and asecond end. The second end of the body is coupled to the motor pack. Thefirst end of the body is coupled to the wheel.

In one aspect, the preload engage/disengage mechanism also includes apreload engagement arm that has a first end and a second. The first endof the preload engagement arm is coupled to the first pivot pin. Arolling pin is mounted in the second end of the preload engagement arm.

In this aspect, the preload engage/disengage mechanism further includesa second pivot pin and a preload engage/disengage arm rotatably coupledto the second pivot pin. The preload engage/disengage arm is couplableto and decouplable from the rolling pin. A torsional spring is mountedon the second pivot pin and coupled to the preload engage/disengage arm.The torsional spring is configured to provide a torque on the preloadengage/disengage arm to hold the preload engage/disengage arm in adisengaged position from the rolling pin.

The preload engage/disengage mechanism still further includes anelectronic actuator coupled to the preload engage/disengage arm and tothe controller. If an engage command from the controller is received bythe electronic actuator, the electronic actuator provides a torque onthe preload engage/disengage arm to hold the preload engage/disengagearm in an engaged position with respect to the rolling pin, this isreferred to as the preload being engaged. The preload engage/disengagemechanism also includes an emergency instrument release button coupledto the preload engage/disengage arm.

In another aspect, an apparatus includes a surgical instrumentmanipulator assembly, an insertion assembly, and a controller. Thesurgical instrument manipulator assembly includes a housing, a motorpack and a preload assembly. The motor pack is movably mounted in thehousing. The preload assembly includes a preload engage/disengagemechanism. The insertion assembly is coupled to the surgical instrumentmanipulator assembly. The insertion assembly includes a preload track.The controller is coupled to the surgical instrument manipulatorassembly, the insertion assembly, and the preload assembly. Thecontroller is configured to command the insertion assembly to move thepreload assembly until the preload assembly is fully withdrawn; tocommand the preload engage/disengage mechanism to engage a preload, ifthe preload assembly is fully withdrawn; and to command the insertionassembly to move the preload assembly to a home position after engagingthe preload. In this apparatus, the preload engage/disengage mechanismis the same as that described above.

A method includes releasing a preload force on a motor pack of asurgical instrument manipulator assembly by moving the surgicalinstrument manipulator assembly to a fully withdrawn position.

Another method includes moving, by a controller, a surgical instrumentmanipulator assembly to a fully withdrawn position. The method alsoincludes issuing, by a controller, a command to a preload assembly ofthe surgical instrument manipulator assembly to engage a preload. Themethod further includes moving, by the controller, the surgicalinstrument manipulator assembly to a home position after the preload isengaged. This method can also include moving, by the controller, thesurgical instrument manipulator assembly to a fully withdrawn positionto automatically release the preload.

A surgical apparatus includes a surgical instrument manipulator assemblyand a sterile adapter assembly. The sterile adapter assembly is mountedin the distal face of the surgical instrument manipulator assembly. Whenthe preload assembly configures the surgical instrument manipulatorassembly to apply a preload force on the sterile adapter assembly, thesterile adapter assembly is removable from the distal face of thesurgical instrument manipulator.

In one aspect, the sterile adapter assembly includes a mechanicalsterile adapter assembly removal lockout and a mechanical surgicalinstrument removal lockout. The surgical apparatus, in one aspect, alsoincludes a surgical instrument is mounted in the sterile adapterassembly. Mounting the surgical instrument in the sterile adapterassembly activates the mechanical sterile adapter assembly removallockout.

In another aspect, the surgical apparatus also includes an insertionassembly connected to the surgical instrument manipulator assembly. Ifthe surgical instrument manipulator assembly is moved in a distaldirection a predetermined distance, the surgical instrument manipulatorassembly activates the sterile adapter removal lockout.

In this aspect, the surgical instrument manipulator assembly alsoincludes a clutch button. The clutch button and the emergency releasebutton are the only user operated interfaces of the surgical instrumentmanipulator assembly.

In one aspect, the sterile adapter assembly includes a frame In thisaspect, the mechanical surgical instrument removal lockout includes amovable body moveably mounted in the frame of the sterile adapterassembly. In a first position of the movable body, the surgicalinstrument can be removed from the sterile adapter assembly, while in asecond position of the moveable body, the surgical instrument is lockedin place in the sterile adapter assembly.

In yet another aspect, the sterile adapter assembly further includes abeam having a first end and a second end, where the first end isopposite the second end. The beam is pivotally connected to a frame ofthe sterile adapter assembly. A plurality of hook extensions extendsfrom the second end of the beam. Each of the plurality of hook extensionincludes a hook configured to engage a hook receiver in a surgicalinstrument manipulator assembly. A sterile adapter assembly releasebutton is coupled to the first end of the beam. Depressing the sterileadapter assembly release button in a first direction causes theplurality of hook elements to move in a second direction to disengageeach hook from the hook receiver. The mechanical sterile adapterassembly removal lockout comprises the first end of the beam where ifthe surgical instrument is mounted in the sterile adapter assembly, thesurgical instrument prevents movement of the sterile adapter assemblybutton in the first direction and so disables removal of the sterileadapter assembly from the surgical instrument manipulator assembly.

In one aspect, a surgical instrument manipulator assembly includes ahousing, a clutch button mounted in the housing, and a preload assemblyincluding an emergency instrument release button. The clutch button andthe emergency instrument release button are the only user operatedbuttons of the surgical instrument manipulator assembly.

A method includes moving a combination of a surgical instrumentmanipulator assembly and a sterile adapter assembly from a secondposition where the surgical instrument manipulator assembly exerts asecond preload force on the sterile adapter assembly to a first positionwhere the surgical instrument manipulator assembly exerts a firstpreload force on the sterile adapter assembly, where the second preloadforce is larger than the first preload force. The method also includesremoving the sterile adapter assembly from the surgical instrumentmanipulator assembly with the first preload force being exerted on thesterile adapter assembly.

In a further aspect, a computer-assisted surgical system includes asurgical instrument manipulator assembly and a controller. The surgicalinstrument manipulator assembly includes a preload assembly. Thecontroller is coupled to the preload assembly. The controller directlycontrols the preload provided by the preload mechanism through commandsto the preload assembly.

In this aspect the surgical instrument manipulator assembly includes ahousing and a motor pack movably mounted in the housing. The preloadassembly is connected to the housing. The preload assembly is configuredto move the motor pack relative to the housing under control of thecontroller.

The preload assembly includes a motor and a nut. The motor is coupled tothe controller. The nut is coupled to the motor so that the motor movesthe nut in a first direction and in a second direction. The preloadassembly also includes an arm coupled to the motor pack and a preloadrelease lever pivotally mounted on the arm. The preload release lever iscouplable to and decouplable from the nut. If the preload release leveris coupled to the nut, movement of the nut is transferred to the arm.The preload assembly also includes an emergency instrument releasebutton coupled to the preload release lever.

In a still further aspect, a computer-assisted surgical system includesa surgical instrument manipulator assembly, an insertion assembly, and acontroller. The surgical instrument manipulator assembly includes ahousing, a motor pack, and a preload assembly. The motor pack is movablymounted in the housing. The insertion assembly is coupled to thesurgical instrument manipulator assembly to move the surgical instrumentmanipulator assembly. The controller is coupled to the surgicalinstrument manipulator assembly, to the insertion assembly, and to thepreload assembly. The controller is configured to command the preloadassembly to change a position of the motor pack with respect to housingof the motor pack independent of the position of the insertion assemblyrelative to the preload assembly and independent of whether theinsertion assembly is moving or stationary.

Another method includes controlling a preload force on a motor pack of asurgical instrument manipulator assembly by a controller issuing acommand directly to a preload assembly.

Yet another method includes moving, by a controller, a motor pack of asurgical instrument manipulator assembly relative to a housing of thesurgical instrument manipulator assembly from a no preload position to alow preload position while the surgical instrument manipulator assemblyremains at a fixed position, such as the home position. This methodfurther includes moving, by the controller, the motor pack of a surgicalinstrument manipulator assembly relative to a housing of the surgicalinstrument manipulator assembly from a high preload position to a lowpreload position irrespective of control of an insertion assembly onwhich the surgical instrument manipulator is mounted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an illustration of a prior art teleoperated minimallyinvasive surgical system.

FIG. 1B is an illustration of a prior art surgical device assembly.

FIG. 2 is an illustration of a teleoperated system that includes aninstrument manipulator assembly with a preload assembly that includesautomated preload engagement/disengagement and only an emergencyinstrument release button and a clutch button.

FIG. 3A is a more detailed illustration of the configuration of thesurgical device assemblies in FIG. 2, with all the assemblies at a homeposition.

FIG. 3B is a more detailed illustration of the configuration of thesurgical device assemblies in FIG. 2, with some of the assemblies at anextended position.

FIGS. 4A to 4G are block diagrams that illustrate the mounting of asterile adapter assembly and an instrument on an instrument manipulatorassembly, operation of a preload mechanism, instrument removal lockout,sterile adapter removal lockout, automatic preload release, andautomatic preload reset.

FIG. 5 illustrates a sterile surgical drape.

FIG. 6A is an illustration of the patient side support system of FIG. 2Ain a configuration for draping.

FIGS. 6B and 6C illustrate drape alignment and mounting receptacles on alink of the patient side support system.

FIG. 7A illustrates a surgical drape installation package being movedinto position for mounting on a platform on one end of a link of thepatient side support system.

FIG. 7B shows the surgical drape installation package mounted on theplatform of FIG. 7A.

FIG. 8 is a state diagram for an instrument manipulator assembly.

FIG. 9A illustrates the instrument manipulator assembly of FIG. 2affixed to an insertion assembly that in turn is attached to aninsertion axis base assembly.

FIGS. 9B to 9F are illustrations of a sterile adapter assembly thatincludes mechanical lockouts.

FIGS. 10A and 10B illustrate installing the sterile adapter assembly ofFIGS. 9B to 9F on another instrument manipulator assembly.

FIG. 10C is a partial cutaway drawing that illustrates features of thesterile adapter assembly and the instrument manipulator assembly.

FIGS. 11A and 11B are more detailed illustrations of an example of oneof the instruments of FIG. 2.

FIGS. 12 to 14 illustrate stages in the mounting of the instrument inthe sterile adapter assembly.

FIG. 15 is an illustration of the surgical instrument of FIGS. 11A and11B mounted in the sterile adapter assembly of FIGS. 9B to 9F toactivate the sterile adapter assembly lockout mechanism.

FIG. 16 is a more detailed illustration of a prior art insertionassembly.

FIGS. 17A and 17B illustrate a preload assembly in greater detail.

FIG. 17C is a side view of a torsional spring in the preload assembly ofFIGS. 17A and 17B.

FIGS. 18A to 18E illustrate the automatic engagement of the preload by acontroller.

FIGS. 19A to 19C illustrate the automatic disengagement of the preloadby the controller.

FIGS. 20A to 20C illustrate different preload states of an instrumentmanipulator assembly having a preload assembly that is directlycontrolled by a controller.

FIGS. 20D and 20E illustrate a mechanical instrument removal lockoutassembly having different mechanical instrument removal lockout statesthat are directly controlled by a controller.

FIGS. 21A to 21C illustrate one aspect of the preload assembly of FIGS.20A to 20C in further detail.

In the drawings, for single digit figure numbers, the first digit in thereference numeral of an element is the number of the figure in whichthat element first appears. For double-digit figure numbers, the firsttwo digits in the reference numeral of an element is the number of thefigure in which that element first appears.

DETAILED DESCRIPTION

In one aspect, a computer-assisted teleoperated system 200, sometimesreferred to as system 200, (FIG. 2), e.g., a minimally invasivecomputer-assisted teleoperated system, includes a patient-side supportsystem 210 having an arm 220. At an end of arm 220 is an entry guidemanipulator assembly 230 (also called entry guide manipulator 230).Mounted on entry guide manipulator 230 is a master instrumentmanipulator 280 that in turn supports multiple surgical deviceassemblies. In one aspect, a surgical device assembly includes aninstrument manipulator assembly 240, an instrument sterile adapterassembly 250, and an instrument 260. In one aspect, instrument sterileadapter assembly 250 is attached to a sterile drape that is used todrape entry guide manipulator 230 and each instrument manipulatorassembly 240.

Instrument manipulator assembly 240 is sometimes referred to asinstrument manipulator assembly 240. Instrument sterile adapter assembly250 is sometimes referred to as sterile adapter assembly 250.

Entry guide manipulator 230 changes the pitch and yaw of the surgicaldevice assemblies as group. A main tube of each instrument 260 extendsthrough a different channel in a single port entry guide 270. Singleport entry guide 270 is mounted in a cannula, in this aspect. Singleport refers to a single access location (e.g., a single incision, asingle natural orifice, and the like) to a surgical site inside thepatient.

As used herein, a cannula is a tube that passes through the patient'sbody wall, and that comes in direct contact with the patient. Thecannula generally does not slide in and out relative to the patient, butthe cannula can pitch and yaw around a point on its axis called theremote center of motion.

As used herein, singe port entry guide 270 is a tube through which allsurgical instruments and a camera instrument must pass to reach alocation inside the patient. Entry guide 270 has separate lumens foreach instrument. Entry guide 270 passes through the cannula, and maytwist relative to the cannula.

A controller 290 is coupled to a surgeon's control console (not shown)and to patient-side support system 210. Controller 290 represents thevarious controllers in system 200. Controller 290 sends second controlcommands to instrument 260 in response to first control commands. Thefirst control commands are based on movements of masters in a surgeon'scontrol console by a surgeon. A display control module in systemcontroller 290 also updates a stereoscopic view of the surgical sitegenerated by a display device in the surgeon's control console as slaveinstrument 260 moves in response to the second control commands.

Although described as controller 290, it is to be appreciated thatcontroller 290 may be implemented in practice by any combination ofhardware, software that is executed on a processor, and firmware. Also,its functions, as described herein, may be performed by one unit ordivided up among different components, each of which may be implementedin turn by any combination of hardware, software that is executed on aprocessor, and firmware. When divided up among different components, thecomponents may be centralized in one location or distributed acrosssystem 200 for distributed processing purposes. A processor should beunderstood to include at least a logic unit and a memory associated withthe logic unit.

As explained more completely below, in one aspect, controller 290releases a preload force on a motor pack of instrument manipulatorassembly 240 by moving the instrument manipulator assembly 240 to afully withdrawn position, which is proximal to the home position.

To engage the preload, controller 290 moves instrument manipulatorassembly 240 to a fully withdrawn position, and then controller 290issues a command to a preload assembly of instrument manipulatorassembly 240 to engage the preload. After the preload is engaged,controller 290 moves instrument manipulator assembly 240 to a homeposition. Here, when it is stated that controller 290 preforms an act,it means that controller issues a command or signal to a component thatperforms the act.

In another aspect, controller 290 can change the preload independent ofthe position of instrument manipulator assembly 240 and independent ofwhether instrument manipulator assembly 240 is moving or stationary.Controller 290 controls a motor within the preload assembly that in turndetermines the preload applied by the preload assembly. Commands fromcontroller 290 to the insertion assembly to move instrument manipulatorassembly 240 do not affect the preload in this aspect. The preload isunder the direct control of controller 290, and can be changed bycontroller 290 as necessary.

As described more completely below, computer-assisted teleoperatedsystem 200 includes some features of a previous system, which arepresented in:

-   -   U.S. Patent Application Publication No. US 2016/0184037 A1        (disclosing “PRELOADED SURGICAL INSTRUMENT INTERFACE”);    -   U.S. Patent Application Publication No. US 2016/0184036 A1        (disclosing “VARIABLE INSTRUMENT PRELOAD MECHANISM CONTROLLER”);    -   U.S. Patent Application Publication No. US 2016/0184035 A1        (disclosing “ACTUATOR INTERFACE TO INSTRUMENT STERILE ADAPTER”);    -   PCT International Publication No. WO 2015/023834 A1 (disclosing        “INSTRUMENT STERILE ADAPTER DRIVE FEATURES”);    -   PCT International Publication No. WO 2015/023840 A1 (disclosing        “INSTRUMENT STERILE ADAPTER DRIVE INTERFACE”); and    -   PCT International Publication No. WO 2015/023853 A1 (disclosing        “ROBOTIC INSTRUMENT DRIVEN ELEMENT”), each of which is        incorporated herein by reference in its entirety.        The features common to both the prior system and system 200 are        not described in detail herein to avoid detracting from the        inventive aspects described herein.

In one aspect of the system described in the above cited publications,each instrument manipulator assembly included a sterile adapter releaselatch, a clutch button, and a preload release button. As explained morecompletely, the instrument manipulator assemblies in system 200 do notinclude a sterile adapter release latch or a pre-load based sterileadapter release lock-out.

Instrument manipulator assembly 240 includes a clutch button mounted inthe housing of instrument manipulator assembly 240 and an emergencyinstrument release button. The clutch button and the emergency releasebutton are the only user operated buttons of instrument manipulatorassembly 240. Thus, the clutch button and the emergency release buttonare the only user operated interfaces of the instrument manipulatorassembly 240. The reduction in the number of buttons on instrumentmanipulator assembly 240 improves the user experience by minimizing thelikelihood that a user mistakenly presses the wrong button or delays ata critical time due to confusion about the function of the variousbuttons on instrument manipulator assembly 240.

In one aspect of the system described in the above cited publications,the preload release button had a dual function. The preload releasebutton was pushed to defeat a sterile adapter removal lockout feature sothat the sterile adapter could be removed. The preload release buttonalso was used to release the preload in an emergency situation. Incontrast, as explained more completely below, the emergency instrumentrelease button on each of the plurality of instrument manipulators ofsystem 200 is used only to release a preload force on a disk stack. Inaddition, to facilitate the draping of system 200, the release of thepreload and activation of the preload is under the control of controller290 so that the preload can be released to facilitate the drapingprocess and can be activated after draping is completed.

FIGS. 3A and 3B are illustrations of four surgical device assemblies 300mounted on entry guide manipulator 230. In FIG. 3A, surgical deviceassemblies 300 are positioned at an initial position, e.g., a firstlocation, sometimes referred to as the “home position.” The mechanicalinterface includes a disk stack between a motor in instrumentmanipulator assembly 240 and a shaft in the transmission unit ofinstrument 260. In the configuration of FIG. 3A, following draping, afirst preload force is applied on the disk stack, e.g., a firstpredetermined force is applied on the disk stack.

With this first preload force, the mechanical interface may have somebacklash because the first preload force is not sufficient to clamp thedisks in the disk stack tightly enough together to prevent relativemotion between the disks in the mechanical interface. However, thedesign of disks in the disk stack in the mechanical interface incombination with the first preload force ensures that the disks in thedisk stack remain engaged, e.g., partially coupled, until the backlashis minimized.

With the first preload force, which is a low preload force, the disks inthe mechanical interface have zero backlash up to a first torque level,e.g., 1.17 in-lb assuming a friction coefficient of 0.1. Above the firsttorque level, there may be a known small backlash, for example 1.13degrees. Since, as described more completely below, a force sufficientto spin the disks to overcome friction and dynamically mate the disksquickly is used, this force typically provides more than the firsttorque level. In this instance, the disks in the mechanical interfacehave non-zero backlash. Thus, the mechanical interface is said to havenon-zero backlash in this instance.

In FIG. 3B, three of the four surgical device assemblies have been moveddistally. Arrow 390 defines the distal and proximal directions. Here,the distal direction is towards patient 201 and away from masterinstrument manipulator 280. The proximal direction is away from patient201 and towards master instrument manipulator 280. The distal directionis an example of a first direction and the proximal direction is anexample of a second direction that is opposite to the first direction.

As surgical device assembly 300 moves distally on insertion assembly331, the preload force on the disk stack is automatically increased fromthe first preload force to a second preload force. The second preloadforce is an example of a second predetermined force. The second preloadforce reduces the backlash of the mechanical interface, i.e., thebacklash between the disks in the disk stack, to zero for torque levelsused in surgical procedures.

In one aspect, the second preload force is a high preload force, e.g.,2.3 lb. As just described, the disks in the mechanical interface, andhence the mechanical interface, have zero backlash at torque levels usedin surgical procedures. In one example if the coefficient of friction isassumed to be 0.1, the mechanical interface has zero backlash for torquelevels up to 4.9 in-lb. For instrument 260 to apply surgically usefulforces at the end effector, a certain torque must be applied to thedisks in the mechanical interface. This is deemed a surgically usefultorque. In one example, a surgically useful torque may be 4.425 in-lb,and so the mechanical interface has zero backlash for torque levels usedin surgical procedures in this aspect.

FIGS. 4A to 4G are block diagrams that illustrate the mounting of asterile adapter assembly and an instrument on an instrument manipulatorassembly. Other aspects illustrated in FIGS. 4A to 4G include operationof a preload engage/disengage mechanism to reduce backlash, instrumentremoval lockout, sterile adapter assembly removal lockout, preloadrelease, and automatic preload reset. These mechanical lockout featuresare used to assure that system 200 cannot have illegal transitionsbetween the different states of system 200.

FIGS. 4A to 4G are not to scale. Arrow 390 in FIGS. 4A and 4G shows theproximal and distal directions in each of FIGS. 4A to 4G.

FIG. 4A shows an instrument manipulator assembly 440 affixed toinsertion assembly 431. Instrument manipulator assembly 440 is oneexample of instrument manipulator assembly 240. Insertion assembly 431is an example of insertion assembly 331.

Instrument manipulator assembly housing 448, sometimes referred to ashousing 448, is fixedly attached to a distal end of insertion assembly431, and so instrument manipulator assembly housing 448 moves withmovement of insertion assembly 431. However, a motor pack 446 withininstrument manipulator assembly housing 448 can move on rail 439. Motorpack 446 can move in the distal and proximal directions relative toinstrument manipulator assembly housing 448. Motor pack 446 is coupledto instrument manipulator assembly housing 448 by a motor pack returnspring 447, sometimes referred to as return spring 447.

Motor pack 446 is movably coupled to insertion assembly 431 by preloadassembly 480. Preload assembly 480 rides on a preload track in insertionassembly 431, in one aspect. As explained more completely below, aspreload assembly 480 moves in the distal direction, preload assembly 480provides a longitudinal force in the distal direction on motor pack 446.Preload assembly 480 includes an emergency instrument release button482.

Motor pack 446 includes a plurality of drive units 441. Plurality ofdrive units 441 includes a plurality of drive motors and a plurality ofdrive output assemblies. Each drive motor in the plurality of drivemotors is coupled to a corresponding drive output assembly 443 in theplurality of drive output assemblies.

Drive output assembly 443 includes a preload spring assembly and a driveoutput disk 445. Drive output assembly 443 also includes a low backlashcoupler positioned between the preload spring assembly and drive outputdisk 445. Drive output disk 445 is coupled to the low backlash couplerby a set of input pins.

Drive output disk 445 is a cylindrical disk that includes a distal endsurface. The distal end of each drive output disk 445 has a driveinterface. The drive interface includes drive dogs and alignmentelements. The drive dogs extend in a distal direction from the distalend surface. An example of a motor pack and a plurality of drive unitssuitable for use as motor pack 446 including a plurality of drive units441 are described in U.S. Patent Application Publication No. US2016/0184037 A1 (disclosing “PRELOADED SURGICAL INSTRUMENT INTERFACE”),which was previously incorporated by reference.

Motor pack 446 includes a plurality of hard-stops 437. Each of theplurality of hard-stops 437 is configured to extend from a distal faceof motor pack 446 when there is a high preload on motor pack 446.

FIG. 4A shows instrument manipulator assembly 440 with motor pack 446 ata no preload position 432, i.e., with the preload mechanism released. Inthis configuration, if the preload mechanism is not engaged, e.g., thepreload is not engaged, there is no preload on motor pack 446 so thatthe plurality of drive output disks including drive output disk 445 donot extend from a distal face of instrument manipulator assembly housing448 irrespective of the position of instrument manipulator assembly 440with respect to the home position. The distal face of motor pack 446 isat no preload position 432. Conversely, if the preload mechanism isengaged and instrument manipulator assembly 440 is at a home position,there is a first preload force on motor pack 446 so that the pluralityof drive output disks including drive output disk 445 extend from adistal face of instrument manipulator assembly housing 448. The occurswhen motor pack is at a low preload position 433 relative to instrumentmanipulator assembly housing 448.

Typically, prior to use, at least a portion of patient side supportsystem 210 is draped with a sterile surgical drape prior to using system200. Prior to considering the mechanical lockout safety features ofsystem 200, as presented in FIGS. 4B to 4G, it is helpful to consideraspects of patient side support system 210 and a sterile surgical drape,because some of the control states of instrument manipulator assembly440 are dependent upon signals provided during the draping process.

In one aspect, a sterile surgical drape 560 (FIG. 5), sometimes referredto as surgical drape 560, is use to drape a portion of patient sidesupport system 210. In one aspect, sterile surgical drape 560 includes afirst portion 561 and a second portion 562.

First portion 561 of sterile surgical drape 560 is connected to astationary part of a rotatable seal 565 and second portion 562 isconnected to a movable part of rotatable seal 565. In one aspect,rotatable seal 565 is labyrinth seal, where the stationary part is aroll cover portion of the labyrinth seal, and the movable part is a basecomb portion of the labyrinth seal.

Second portion 562 of sterile surgical drape 560, in one aspect,includes a plurality of drape sleeves 562-1, 562-2, a plurality of boots563-1, 563-2, and a plurality of mechanical interface elements 564-1,564-2. Typically, sterile surgical drape 560 includes one drape sleeve,one boot, and one mechanical interface element for each instrumentmanipulator assembly 240 in system 200.

Each of plurality of mechanical interface elements 564-1, 564-2 iscoupled to a corresponding boot in plurality of boots 563-1, 563-2. Eachof plurality of boots 563-1, 563-2 is coupled to a corresponding drapesleeve in plurality of drape sleeves 562-1, 562-2. An opening of eachdrape sleeve in plurality of drape sleeves 562-1, 562-2 is connected tothe movable portion of rotatable seal 565, which, in one aspect, is adisc with ribs that form a plurality of wedge-shaped “frames” withapertures, each of the frames is sized to circumscribe an instrumentmanipulator assembly. The open end of each of plurality of drape sleeves562-1, 562-2 is coupled to a different one of the plurality ofwedge-shaped frames. Each of plurality of boots 563-1, 563-2 fits aroundan instrument manipulator assembly that is coupled by an insertionassembly to an entry guide manipulator assembly.

FIG. 6A is an illustration of one aspect of a patient side supportsystem 210 in a configuration to initiate draping. As illustrated inFIGS. 2 and 6A, entry guide manipulator assembly 230, sometimes referredto as entry guide manipulator 230, includes four links 613, 615, 617,and 619 coupled by joints. As shown in FIG. 6A, a manipulator assemblyyaw joint 611 is coupled between an end of setup link 606 and a secondend, e.g., a proximal end, of a first manipulator link 613. Yaw joint611 allows first manipulator link 613 to move with reference to link 606in a motion that may be arbitrarily defined as “yaw” around amanipulator assembly yaw axis.

In one embodiment, setup link 606 is rotatable in a horizontal or x, yplane and yaw joint 611 is configured to allow first manipulator link613 in entry guide manipulator 230 to rotate about a yaw axis. Setuplink 606, yaw joint 611, and first manipulator link 613 provide aconstantly vertical yaw axis for entry guide manipulator 230.

A first end of first manipulator link 613 is coupled to a second end ofa second manipulator link 615 by a first actively controlled rotationaljoint 614. A first end of second manipulator link 615 is coupled to asecond end of a third manipulator link 617 by a second activelycontrolled rotational joint 616. A first end of third manipulator link617 is coupled to a distal portion of a fourth manipulator link 619 by athird actively controlled rotational joint.

In one embodiment, links 615, 617, and 619 are coupled together to actas a coupled motion mechanism. Coupled motion mechanisms are well known(e.g., such mechanisms are known as parallel motion linkages when inputand output link motions are kept parallel to each other). For example,if rotational joint 614 is actively rotated, joints 616 and 618 are alsoactively rotated so that link 619 moves with a constant relationship tolink 615. Therefore, it can be seen that the rotational axes of joints614, 616, and 618 are parallel. When these axes are perpendicular to therotational axis of joint 611, links 615, 617, and 619 move withreference to link 613 in a motion that may be arbitrarily defined as“pitch” around a manipulator assembly pitch axis. Since links 615, 617,and 619 move as a single assembly, first manipulator link 613 may beconsidered an active proximal manipulator link, and second throughfourth manipulator links 615, 617, and 619 may be consideredcollectively an active distal manipulator link.

In one aspect, a first manipulator link 613 includes a first end 613-1(FIG. 6B) that includes an alignment receptacle 613C and a second end613-2 (FIG. 6C) that includes two alignment receptacles 613A, 613B.Attachment devices—one for each of the alignment receptacles—are affixedto surgical drape 560. In one aspect, each of alignment receptacles613A, 613B, 613C includes a magnet and the attachment devices affixed tosurgical drape 560 are shaped to fit in alignment receptacles 613A,613B, 613C, and are made of a metal that is attracted to and coupleswith the magnet.

In one aspect, each of alignment receptacles 613A, 613B, 613C includesan attachment senor or has an attachment sensor associated with thealignment receptacle. When the attachment sensors detect that surgicaldrape 560 has been attached to patient side support system 210, a drapeattached signal is sent to controller 290 indicating the attachment ofsurgical drape 560. Specifically, when an attachment device attached tosurgical drape 560 is engaged with the corresponding alignmentreceptacle to attach surgical drape 560 to a portion of patient sidesupport system 210, the attachment sensor detects the presence of theattachment device.

A sensor configured to detect the presence of a drape attachment devicemay be, for example, an inductive sensor. An inductive sensor emits amagnetic field that is sensed by the sensor, such as via an inductionloop. When a metallic member, i.e., the attachment device, is proximatethe sensor, the metallic member changes the inductance, which isdetected by the sensor to indicate the presence of the attachmentdevice. The use of an inductive sensor is illustrative only and is notintended to be limiting.

A sensor to detect the attachment of surgical drape 560 may be, forexample, an optical sensor. An optical sensor may use, for example,light reflected off the drape attachment device or light reflected offdrape 560 itself to detect when surgical drape 560 has been attached. Inanother example, an optical sensor may be a sensor that emits a lightbeam and receives the light beam, but senses the presence of surgicaldrape 560 when the surgical drape 560 or the attachment device breaksthe beam. A sensor may also be a capacitive sensor that senses a changein capacitance that occurs when surgical drape 560 has been attached. Inanother example, a sensor may be a switch that is mechanically depressedor otherwise switched by the drape attachment device or surgical drape560 when surgical drape 560 is attached to link 613 of patient sidesupport system 210.

FIG. 7A illustrates a surgical drape installation package 770 beingmoved into position for mounting on platform 632 on one end of link 619.Surgical drape installation package 770 includes a surgical drapeinstallation aid on which sterile surgical drape 560 is mounted.

FIG. 7B shows surgical drape installation package 770 mounted onplatform 632. In particular, each of a plurality of latches of rotatableseal 565 has been engaged in a corresponding latch receptacle inplatform 632. An example of a surgical drape installation package ispresented in commonly assigned and commonly filed U.S. PatentApplication No. 62/362,190 (disclosing “Surgical Drape InstallationAid,” filed Jul. 14, 2016), which is incorporated herein by reference inits entirety.

When surgical drape installation package 770 is mounted on platform 632,a drape mount sensor sends a drape mounted signal to controller 290indicating the mounting of surgical drape installation package 770. Inone aspect, the drape mount sensor includes a mechanical switch, e.g., aplunger, which is activated by mounting of the stationary part of arotatable seal 565. Alternatively, instead of a mechanical sensor, thedrape mount sensor could be an inductive sensor, a capacitive sensor, oran optical sensor similar to those described above.

Returning to the consideration of FIGS. 4B to 4G, these figures aredescribed in combination with state workflow diagram 800 (FIG. 8) ofinstrument manipulator assembly 240 and instrument manipulator assembly440. In FIG. 8, the different states in workflow diagram 800 are dividedinto a NORMAL MODE 891 and an ILLEGAL STATE MODE 892. The normal pathbetween states is indicated by the heavy solid line in FIG. 8.

In START state 801 for instrument manipulator assembly 440 ofcomputer-assisted teleoperated system 200, the preload engage/disengagemechanism of preload assembly 480 is disengaged. Thus, there are nopreload forces on the drive disks of motor pack 446, e.g., motor pack446 is at no preload position 432 relative to instrument manipulatorhousing 448. Also, in START state 801, instrument manipulator assembly440 (FIG. 4A) is moved so that instrument manipulator assembly 440 is ata home position, if instrument manipulator assembly 440 is not alreadyat that position. Hence, in START state 801 the preload engage/disengagemechanism is not activated, and so as instrument manipulator assembly440 is moved by insertion assembly 431, no pre-load forces are created.

In response to a command from a user interface to deploy for draping,INSTALL DRAPE act 815 is initiated. In INSTALL DRAPE act 815, entryguide manipulator 230 is moved by controller 290 to the position shownin FIG. 6A, and master instrument manipulator 280 moves the plurality ofinstrument manipulator assemblies as far apart as possible to facilitatedraping. Next, surgical drape installation package 770 is mounted onentry guide manipulator assembly platform 632, and in response to themounting of package 770, a drape mounted signal is sent to controller290.

First portion 561 of sterile surgical drape 560 is extended over links619, 617, and 615 of entry guide manipulator 230. Finally, first portion561 is attached to alignment receptacles 613A, 613B, and 613C of link613. As explained above, the attachment of sterile drape 560 to link 613causes a drape attached signal to be sent to controller 290. Uponcompletion of draping the links of entry guide manipulator 230, the usertypically moves entry guide manipulator 230 from the tilted positionshown in FIGS. 7A and 7B back to the vertical position.

When controller 290 receives the drape attached signal after receivingthe drape mounted signal, the state of instrument manipulator assembly440 transitions from START state 801 to DRAPE MOUNTED state 811,sometime referred to as state 811, in DRAPING process 810. When state811 is entered, instrument manipulator assembly 440 is configured sothat if a user pushes on instrument manipulator assembly 440, instrumentmanipulator assembly 440 automatically moves in the direction of theforce applied by the user. This helps the user to position a sleeve ofsterile drape 560 around insertion assembly 431 and instrumentmanipulator assembly 440.

Thus, in EXTEND INSERTION act 816, a user pushes instrument manipulatorassembly 440 in the distal direction. In response to the force suppliedby the user, controller 290 causes insertion assembly 430 to moveinstrument manipulator assembly 440 in the distal direction. One exampleof a controller that moves an instrument manipulator in response to auser tap is described in commonly assigned and commonly filed U.S.Patent Application No. 62/362,192 (disclosing “Automatic ManipulatorAssembly Deployment for Draping,” filed Jul. 14, 2016), which isincorporated herein by reference in its entirety. After insertionassembly 431 is extended, DRAPE MOUNTED state 811 transfers to INSERTIONEXTENDED state 812. Even though insertion assembly 431 is extended,there are no preload actions, because the preload engage/disengagemechanism of preload assembly 480 is disengaged.

With instrument manipulator assembly 440 in INSERTION EXTENDED state812, in INSTALL STERILE ADAPTER act 817, a surgical device interfaceelement 450, e.g., a sterile adapter assembly, is mounted on instrumentmanipulator assembly 440 to obtain the configuration shown in FIG. 4B.Surgical device interface element 450 is an example of sterile adapterassembly 250. Since the preload engage/disengage mechanism is notengaged, motor pack 446 is not displaced distally with respect tohousing 448, and so mounting surgical device interface element 450 inthis configuration does not requires compressing the plurality ofpreload spring assemblies including the preload spring assembly in driveoutput assembly 443 during the mounting of surgical device interfaceelement 450.

With no preload force on motor pack 446, surgical device interfaceelement 450 is mounted by moving surgical device interface element 450proximally until hooks on surgical device interface element 450 engagehook receivers in instrument manipulator assembly 440. Unlike the priorart surgical device interface element that required placing one end ofthe surgical device interface element in the instrument manipulatorassembly and pivoting the opposite end of the surgical device interfaceelement until it was latched, surgical device interface element 450 ismoved in a direction perpendicular to a distal face of instrumentmanipulator assembly 440. The mounting of surgical device interfaceelement 450 causes a sensor to send a sterile adapter mounted signal tocontroller 290, which results in the transition to STERILE ADAPTERINSTALLED state 813. In one aspect, the sensor is a mechanical switchthat changes state when surgical device interface element 450 ismounted. Alternatively, the sensor can be an optical sensor, aninductive sensor, or a capacitive sensor, as described above.

Thus, when the user performs INSTALL STERILE ADAPTER act 817, the stateof instrument manipulator assembly 440 goes from INSERTION EXTENDEDstate 812 to STERILE ADAPTER INSTALLED state 813, which is representedin FIG. 4B. In STERILE ADAPTER INSTALLED state 813, insertion assembly431 is extended and the preload engage/disengage mechanism is notengaged.

When a surgical device interface element 450 is mounted on each of theinstrument manipulator assemblies, DRAPING process 810 is complete.Following completion of DRAPING process 810, the user uses the clutchbutton on instrument manipulator assembly 440 to move instrumentmanipulator assembly 440 manually to the home position.

In RETRACT INSERTION act 818, each of the instrument manipulatorassemblies is retracted and returned to the home position. Uponcompletion of RETRACT INSERTION act 818, each of the instrumentmanipulator assemblies is in STERILE ADAPTER INSTALLED, INSERTIONRETRACTED state 820, sometimes referred to as state 820. In state 820,there is no preload force on surgical device interface element 450because the preload engage/disengage mechanism is still disengaged.

Prior to considering further operation of instrument manipulatorassembly 440, the structure of surgical device interface element 450 isfirst described. In this aspect, surgical device interface element 450includes a frame 451 and a movable manipulator-instrument interfaceplate 451C. Moveable manipulator-instrument interface plate 451C,sometimes referred to as movable body 451C, is mounted in frame 451 sothat moveable body 451C can move in the proximal and distal directionswithin frame 451. A plurality of intermediate disks is mounted inmanipulator-instrument interface plate 451C so that each of theplurality of intermediate disks can rotate relative to frame 451.

In this aspect, each intermediate disk in the plurality of disks is thesame, and so intermediate disk 453 is representative of each of theplurality of intermediate disks. Each intermediate disk 453 of theplurality of intermediate disks includes an intermediate driveninterface 455, sometimes referred to as a first intermediate diskinterface, and an intermediate drive interface 456, sometime referred toas a second intermediate disk interface. Intermediate driven interface455 is opposite and removed from intermediate drive interface 456. Inone aspect, intermediate driven interface 455 includes a first alignmentreceptacle and drive dog receptacles. Intermediate drive interface 456includes drive dogs and an engagement structure. An example of amoveable manipulator-instrument interface plate and a plurality ofintermediate disks suitable for use as moveable manipulator-instrumentinterface plate 451C and the plurality of intermediate disks in FIGS. 4Ato 4G are presented in U.S. Patent Application Publication No. US2016/0184035 A1, PCT International Publication No. WO 2015/023834 A1,and PCT International Publication No. WO 2015/023840 A1, each of whichwas previously incorporated by reference.

Movable body 451C also includes a plurality of hard stop receptacles457. Plurality of hard stop receptacles 457 extends from a proximal faceof movable body 451C in a distal direction into movable body 451C.

When instrument manipulator assembly 440 is retracted to the homeposition so that the instrument manipulator assembly 440 is in state820, controller 290 initiates STERILE ADAPTER ENGAGEMENT SEQUENCE act821. In STERILE ADAPTER ENGAGEMENT SEQUENCE act 821, controller 290, inone aspect, commands insertion assembly 431 to move instrumentmanipulator assembly 440 to a first predetermined location, a fullywithdrawn position, which is proximal to the home position.

When instrument manipulator assembly 440 is at the fully withdrawnposition, in one aspect, controller 290 sends an ACTIVATE PRELOAD signal486 to preload engage/disengage mechanism 485 in preload assembly 480.In response to ACTIVATE PRELOAD signal 486, preload engage/disengagemechanism 485 engages the preload, and then controller 290 causesinsertion assembly 431 to return to the home position (FIG. 4C). Asinsertion assembly 431 moves instrument manipulator assembly 440 fromthe fully withdrawn position to the home position, motor pack 446 isdisplaced distally relative to housing 448 of instrument manipulatorassembly 440 from no preload position 432 to low preload position 433.This displacement stretches motor pack return spring 447. The engagementof the preload engage/disengage mechanism holds motor pack 446 in thedistally displaced position relative to housing 448 so that there is apreload force on motor pack 446 in the distal direction.

Thus, when instrument manipulator assembly 440 is moved to homeposition, the displacement of motor pack 446 from no preload position432 to low preload position 433 relative to housing 448 causes a driveinterface of each drive output disk 445 of the plurality of drive outputdisks to contact a corresponding intermediate driven interface 455 ofthe plurality of intermediate driven interfaces of the plurality ofintermediate disks. Thus, the motion of instrument manipulator assembly440 causes each intermediate disk 453 to contact movable body 451C andto move movable body 451C in the distal direction. When movable body451C moves distally as far as possible within frame 451, further motionof drive output disk 445 in the distal direction is inhibited.

Consequently, as instrument manipulator assembly 440 continues to moveto the home position, the preload spring assembly in each drive outputassembly 443 of the plurality of drive output assemblies is compressedso that a preload force is exerted on each drive output disk 445 in theplurality of drive output disks. This preload force is sometime referredto as a first preload force or a low preload force. The preload forcepushes against drive output disk 445 and against a correspondingintermediate driven interface 455 so that the preload force istransferred to each intermediate disk 453 of the plurality ofintermediate disks in surgical device interface element 450. Thisconfiguration is illustrated in FIG. 4C.

When surgical device interface element 450, sometimes referred to as asurgical device interface, is first mounted on instrument manipulatorassembly 440, the elements of intermediate driven interface 455 may notbe aligned with corresponding elements of the drive interface on driveoutput disk 445. If the elements of disks 453 and 445 are not aligned,the two disks are partially coupled together by features in the driveand intermediate driven interfaces, but the two disks are not coupled,e.g., mated, to each other.

Next, in STERILE ADAPTER ENGAGEMENT SEQUENCE act 821, controller 290sends a signal to instrument manipulator assembly 440 to rotate driveoutput disk 445. Rotation of intermediate disk 453 is inhibited anddrive output disk 445 is rotated until the drive interface of driveoutput disk 445 mates with intermediate driven interface 455 ofintermediate disk 453. The partial coupling of the elements of the driveinterface on drive output disk 445 with the corresponding elements ofintermediate driven interface 455 on intermediate disk 453 assures thatthe two disks remain partially coupled under the preload force as thetwo disks rotate. In one aspect, when the two disks are coupled, anothersensor detects a change in a height of the disk stack and sends a signalto controller 290 to stop the rotation of drive output disk 445. Whenthe two disks are mated, the first preload force is on the disks. Themating of drive output disk 445 and intermediate disk 453 is the same asthe mating of corresponding disks as described in U.S. PatentApplication Publication No. US 2016/0184035 A1.

Upon mating of each drive output disk of instrument manipulator assembly440 with the corresponding intermediate disk of surgical deviceinterface element 450 STERILE ADAPTER ENGAGEMENT act 821 is complete.Instrument manipulator assembly 440 is in LOW PRELOAD SET, DISKS ENGAGEDstate 831 of NORMAL USE process 830.

Several acts are possible when instrument manipulator assembly 440 is inin LOW PRELOAD SET, DISKS ENGAGED state 831. For example, a user mayinstall an instrument and continue with a surgical procedure. Uponcompletion of the surgical procedure, as described more completelybelow, NORMAL USE process 830 returns to LOW PRELOAD SET, DISKS ENGAGEDstate 831, and then the user undrapes patient side support system 210.Alternatively, a user can press the emergency instrument release button.Thus, each of these acts is considered in turn.

When instrument manipulator assembly 440 is in LOW PRELOAD SET, DISKSENGAGED state 831, a user may depress emergency instrument releasebutton 482 in EMERGENCY INSTRUMENT RELEASE (EIR) BUTTON act 822.Activating emergency instrument release button 482, e.g., depressingbutton 482, causes preload engage/disengage mechanism 485 to disengagethe preload engage/disengage mechanism of preload assembly 480, and sothe low preload force on the disk stack is released. This returnsinstrument manipulator assembly 440 to STERILE ADAPTER INSTALLED,INSERTION RETRACTED state 820.

Alternatively, when instrument manipulator assembly 440 is in in LOWPRELOAD SET, DISKS ENGAGED state 831, the user can install an instrumentin surgical device interface element 450. Thus, in INSTALL INSTRUMENTact 835, a first end of instrument 460 is slid along a ramp in frame 451of surgical device interface element 450 until instrument 460 is held inthe proper position, as illustrated in FIG. 4E. For this state ofinstrument manipulator assembly 440 with a low preload, movablemanipulator-instrument interface plate 451C is not locked in placed andcan be moved proximally. Thus, as instrument 460 is slid along the ramp,movable manipulator-instrument interface plate 451C is displacedproximally, which further compresses the first preload springassemblies, and so the preload force on the disk stack comprised ofdisks 445, 453, and 463 is said to be about the first preload.

Upon completion of INSTALL INSTRUMENT act 835, instrument manipulatorassembly 440 is in INSTRUMENT INSTALLED state 832, sometimes referred toas state 832. In state 832, the preload on the disk stack comprised ofdisks 445, 453, and 463 is about the first preload and the driveninterface of driven disk 464 probably is not mated with intermediatedrive interface 456 of intermediate disk 453.

Prior to considering INSTRUMENT ENGAGEMENT SEQUENCE act 836, whichchanges the state of instrument manipulator assembly 440 from INSTRUMENTINSTALLED state 832 to INSTRUMENT ENGAGED state 833, the features ofinstrument 460 are briefly considered. Instrument 460, in one aspect, isthe same as the surgical instrument described in U.S. Patent ApplicationPublication No. US 2016/0184037 A1.

In this aspect, instrument 460 (FIG. 4E) includes a body 465 and a maintube 467. Main tube 467 extends distally from body 465. Body 465includes a driven disk receptacle 463, a shaft 466, and a driven disk464. Shaft 466 and driven disk 464 are part of a transmission unit thattransmits received torque through the instrument to one or morecomponents of the instrument.

A proximal end of shaft 466 extends into driven disk receptacle 463, anddriven disk 464 is mounted on the proximal end of shaft 466 so thatdriven disk 464 is positioned in driven disk receptacle 463. Driven disk464 includes a driven interface that interfaces with intermediate driveinterface 456 of intermediate disk 453.

The driven interface of driven disk 464 includes an engagementreceptacle, drive dog receptacles, and a rotation disable element. Therotation disable element includes a rotation locking mechanism. Uponengagement of the rotation disable element, the rotation lockingmechanism engages driven disk receptacle 464 and prevents rotation ofdriven disk 464.

When instrument 460 is coupled to instrument manipulator assembly 440,each driven disk 464 pushes a corresponding intermediate disk 453 insurgical device interface element 450 proximally so that intermediatedisk 453 can rotate freely. This increases the preload force on the diskstack. However, when instrument 460 is first mounted on surgical deviceinterface element 450, the elements of intermediate drive interface 456may not be aligned with corresponding elements of the driven interfaceon driven disk 464. If the elements of the two disks 453 and 464 are notaligned, the two disks are partially coupled together by features inintermediate drive interface 456 and in the driven interface, but thetwo disks are not mated to each other.

When intermediate drive interface 456 of an intermediate disk 453 is notaligned with the corresponding driven interface of driven disk 464, anengagement structure on intermediate drive interface 456 of intermediatedisk 453 engages a rotation disable element on driven disk 464 ofinstrument 460. The rotation disable element includes a rotation lockingmechanism. Upon engagement of the rotation disable element, the rotationlocking mechanism engages driven disk receptacle 464 and preventsrotation of driven disk 464.

When instrument 460 is coupled to instrument manipulator assembly 440,instrument manipulator assembly 440 detects the presence of instrument460, and sends a signal to controller 290. In response to the signal,controller 290 sends a signal to instrument manipulator assembly 440 toperform INSTRUMENT ENGAGEMENT SEQUENCE act 836, sometimes referred to asact 836.

In response to the signal from controller 290, instrument manipulatorassembly 440 rotates drive output disk 445, which in turn rotatesintermediate disk 453. As the intermediate drive interface 456 ofintermediate disk 453 rotates with driven disk 464 fixed in place, eachelement on intermediate drive interface 456 rotates into alignment withthe corresponding element of the driven interface of driven disk 464 andmates with the corresponding element. The coupling of intermediate driveinterface 456 and the driven interface on driven disk 464 releases therotation lock on driven disk 464. Thus, the stack of disks, disks 445,453, and 464, rotates as a unit. When disks 453 and 464 are coupled, thesensor again detects a change in a height of the disk stack and sends asignal to controller 290 to stop the rotation of drive output disk 445.When the stack of disks is mated, the preload force applied to the diskstack is referred to as the first longitudinal force, i.e., the firstpreload force.

Upon the mating of the intermediate disks of surgical device interfaceelement 450 with the disks of instrument 460, instrument manipulatorassembly 440 is in INSTRUMENT ENGAGED state 833, sometimes referred toas state 833, of NORMAL USE process 830. In state 833, instrument 460 isinstalled, the preload is the low preload, and instrument 460 can beremoved from surgical device interface element 450. Instrument 460 canbe removed, because with the low preload, movable manipulator-instrumentinterface plate 451C is not locked in placed, and so can be displaced inthe proximal direction.

In the configuration of FIG. 4E, surgical device interface element 450cannot be removed without removing instrument 460. The installation ofinstrument 460 prevents use of the release buttons on the sides ofsurgical device interface element 450. Thus, surgical device interfaceelement 450 includes a mechanical sterile adapter assembly removallockout so that when instrument 460 is mounted in surgical deviceinterface element 450, instrument 460 activates the mechanical sterileadapter assembly removal lockout.

Unlike the prior system, which inhibited operation of a mechanicalrelease button for the surgical device interface element whenever apreload force was present, there is no interlock on surgical deviceinterface element 450 based on the preload state. The only interlock onsurgical device interface element 450 is a mechanical interlock based onwhether instrument 460 is mounted in surgical device interface element450.

However, in the configuration of FIG. 4E, instrument 460 can still beremoved. As explained more completely in U.S. Patent ApplicationPublication No. US 2016/0184036 A1, in one aspect, there are releasebuttons on each side of instrument 460. Engaging the release buttonscauses a mechanism in instrument 460 to push movable body 451C insurgical device interface element 450 proximally so that intermediatedisk 453 and driven disk 464 are disengaged and instrument 460 can beremoved.

Thus, in REMOVE INSTRUMENT act 838, a user manipulates the releasebuttons on each side of instrument 460, which disengages intermediatedisk 453 and driven disk 464, and then the user slides instrument 460out of surgical device interface element 450. The removal of instrument460 changes the state of instrument manipulator assembly 440 fromINSTRUMENT ENGAGED state 833 back to LOW PRELOAD SET, DISKS ENGAGEDstate 831 of NORMAL USE process 830.

EXTEND INSERTION act 837 changes the state of instrument manipulatorassembly 440 from INSTRUMENT ENGAGED state 833 to INSTRUMENT IN USE HIGHPRELOAD state 834, sometimes referred as state 834. State 834 is in bothNORMAL USE process 830 and INSTRUMENT TIP BEYOND CANNULA state 850.

In EXTEND INSERTION act 837, a distal end of instrument 460 is movedinto and through a cannula by insertion assembly 431 moving instrumentmanipulator assembly 440 in the distal direction. As the distal endinstrument 460 is inserted into the cannula by insertion assembly 431moving instrument manipulator assembly 440, a second preload force isapplied on the disk stack of disks 445, 453, and 464 by preload assembly480 before an end component coupled to main tube 467 protrudes from adistal end of the cannula.

Specifically, as instrument 460 moves distally, preload assembly 480moves distally along the preload track. In one aspect, when instrumentmanipulator assembly 440 moves distally a predetermined distance Zload,preload assembly 480 causes motor pack 446 to move predetermineddistance Zload plus an additional distance A. In another aspect, a motorcontroller moves motor pack 446 distance A with respect to housing 448irrespective of or in coordination with movement of instrumentmanipulator assembly 440 by insertion assembly 431.

In both of these aspects, the movement of motor pack 446 the additionaldistance A with respect to the housing 448 compresses the preload springassembly in each drive output assembly 443 of the plurality of driveoutput assemblies so that a second preload force is exerted on eachdrive output disk 545 in the plurality of drive output disks. The secondpreload force reduces any backlash between rotation of the motor shaftin drive units 441 and rotation of shaft 466 in instrument 460 to lessthan 0.7 degrees before the distal end of instrument 260 exits thecannula.

The movement of motor pack 446 the additional distance A also furtherstretches return spring 447, and in addition inserts each of pluralityof hard stops 437 into a corresponding hard stop receptacle in pluralityof hard stop receptacles 457. Plurality of hard stops 437 prevents anyproximal movement of moveable body 451C in surgical device interfaceelement 450. The combination of plurality of hard stops 437 andplurality of hard stop receptacles 457 forms an instrument removalinterlock and prevents removal of instrument 460. If a person tries toengage the release buttons on instrument 460, the mechanism ininstrument 460 cannot push movable body 451C in surgical deviceinterface element 450 proximally, because plurality of hard stops 437prevents any proximal movement of moveable body 451C, and sointermediate disk 453 and driven disk 464 cannot be disengaged.

The use of plurality of hard stop receptacles 457 is illustrative onlyand is not intended to be limiting. In another aspect, plurality of hardstop receptacles 457 is not used. Instead, plurality of hard stops 437contacts a proximal surface of moveable body 451C and prevents movementof moveable body 451C in the proximal direction. Upon completion ofEXTEND INSERTION act 837, instrument manipulator assembly 440 is inINSTRUMENT IN USE HIGH PRELOAD state 834. In state 834, all the disks inthe disk stack of disks 445, 453, and 464 are engaged and there is asecond preload force on the disk stack. Neither surgical deviceinterface element 450 nor instrument 460 can be removed in state 834.

RETRACT INSERTION act 839 changes the state of instrument manipulatorassembly 440 from INSTRUMENT IN USE HIGH PRELOAD state 834 to INSTRUMENTENGAGED state 833. In RETRACT INSERTION act 839, instrument manipulatorassembly 440 is moved along insertion assembly 431 by the user to thehome position. As instrument manipulator assembly 440 is moved to homeposition, the distal end of instrument 460 no longer extends through thecannula, and the second preload force is changed to the first preloadforce by the preload engage/disengage mechanism 485 of preload assembly480, i.e., as instrument manipulator assembly 440 is withdrawn, motorpack 446 moves from high preload position 434 to low preload position433 relative to housing 448.

If for some reason it is necessary to remove instrument 460 while thedistal tip of instrument 460 extends beyond the distal end of thecannula in state 834, a person pushes emergency instrument releasebutton 482 to implement EMERGENCY INSTRUMENT RELEASE BUTTON act 851.EMERGENCY INSTRUMENT RELEASE (EIR) BUTTON act 851 changes the state ofinstrument manipulator assembly 440 from INSTRUMENT IN USE, HIGH PRELOADstate 834 to NO PRELOAD state 861 of USER INTERFACE (UI) GUIDED RECOVERYprocess 860. The states of USER INTERFACE GUIDED RECOVERY process 860are illegal instrument states.

In EMERGENCY INSTRUMENT RELEASE BUTTON act 851, activating emergencyinstrument release button 482 causes the longitudinal force on motorpack 446 to be released. Consequently, return spring 447 pulls motorpack 446 back to a fully withdrawn position within housing 448.

With motor pack 446 fully withdrawn, plurality of hard stops 437 isretracted from plurality of hard stop receptacles 457 in movable body451C of surgical device interface element 450 and disks 453 and 464 areno longer subject to any preload forces. Thus, the release buttons oninstrument 460 can be used to remove instrument 460 from surgical deviceinterface element 450 at any position of insertion assembly 431.

However, to remove instrument 460 from the cannula, RETRACT INSERTIONact 865 is performed. RETRACT INSERTION act 865 changes the state ofinstrument manipulator assembly 440 from NO PRELOAD state 861 to NOPRELOAD, INSERTION HOME state 862 of USER INTERFACE GUIDED RECOVERYprocess 860. In RETRACT INSERTION act 865, the user engages the clutchbutton of instrument manipulator assembly 440 and moves instrumentmanipulator assembly 440 along insertion assembly 431 to the homeposition.

If instrument manipulator assembly 440 is in INSTRUMENT ENGAGED state833, with instrument 460 is installed and the low preload, EMERGENCYINSTRUMENT RELEASE BUTTON act 867 can be performed. In EMERGENCYINSTRUMENT RELEASE BUTTON act 867, activating emergency instrumentrelease button 482 causes the longitudinal force on motor pack 446 to bereleased. Consequently, return spring 447 pulls motor pack 446 back to afully withdrawn position within housing 448 so that there is no preload.Performance of EMERGENCY INSTRUMENT RELEASE BUTTON act 867, changes thestate of instrument manipulator assembly 440 from INSTRUMENT ENGAGEDstate 833 to NO PRELOAD, INSERTION HOME state 862.

In NO PRELOAD, INSERTION HOME state 862, instrument 460 is withdrawnfrom the cannula, and there is no preload force on the disk stack. Thus,it is safe and possible to remove instrument 460 from surgical deviceinterface element 450.

In REMOVE INSTRUMENT act 866, a user manipulates the release buttons oneach side of instrument 460, which disengages intermediate disk 453 anddriven disk 464, and then the user slides instrument 460 out of surgicaldevice interface element 450. Completion of REMOVE INSTRUMENT act 866changes the state of instrument manipulator assembly 440 from NOPRELOAD, INSERTION HOME state 862 to STERILE ADAPTER INSTALLED,INSERTION RETRACTED state 820.

During a normal surgical procedure, RETRACT INSTRUMENT act 839 isperformed to change the state of instrument manipulator assembly 440from INSTRUMENT IN USE HIGH PRELOAD state 834 to INSTRUMENT ENGAGEDstate 833. Then, REMOVE INSTRUMENT act 838 is performed to change thestate of instrument manipulator assembly 440 from INSTRUMENT ENGAGEDstate 833 to LOW PRELOAD SET, DISKS ENGAGED state 831.

Since the surgical procedure is complete, the drape needs to be removedfrom patient side support system 210. To facilitate UNDRAPING process840, in EXTEND INSERTION act 841, the user uses the clutch button oninstrument manipulator assembly 440 to move instrument manipulatorassembly 440 distally, As instrument manipulator assembly 440 movesdistally, preload assembly 480 moves distally along the preload track.In one aspect, when instrument manipulator assembly 440 moves distally apredetermined distance Zload, preload assembly 480 causes motor pack 446to move predetermined distance Zload plus an additional distance A to ahigh preload position 434 with respect to housing 448. The movement ofmotor pack 446 the additional distance A compresses the preload springassembly in each drive output assembly 443 of the plurality of driveoutput assemblies so that a second preload force is exerted on eachdrive output disk 545 in the plurality of drive output disks. Thissecond preload force is sometimes referred to a high preload forcerelative to the low preload force, described above.

The movement of motor pack 446 the additional distance A also furtherstretches return spring 447, and in addition inserts each of pluralityof hard stops 437 into a corresponding hard stop receptacle in pluralityof hard stop receptacles 457. Plurality of hard stops 437 prevents anyproximal movement of moveable body 451C in surgical device interfaceelement 450. This configuration is illustrated in FIG. 4D. Thus, EXTENDINSERTION act 841 changes the state of instrument manipulator assembly440 from LOW PRELOAD SET STERILE ADAPTER ENGAGED state in NORMAL USEprocess 830 to STERILE ADAPTER INSTALLED, HIGH PRELOAD state 842 inUNDRAPING process 840. In STERILE ADAPTER INSTALLED, HIGH PRELOAD state842, the second preload being is applied to the engaged disks (driveoutput disk 445 and intermediate disk 453) with surgical deviceinterface element 450 mounted on instrument manipulator assembly 440.

In the prior system for either the first preload condition or the secondpreload condition, removal of the sterile adapter required firstdepressing a preload release button on the instrument manipulatorassembly to release the preload condition and also to disable a lock ona sterile adapter release button on the instrument manipulator assembly.The sterile adapter release button on the instrument manipulatorassembly was then used to remove the sterile adapter. See U.S. PatentApplication Publication No. US 2016/0184037 A1 for more details of theprior system.

In contrast, in REMOVE STERILE ADAPTER/DRAPE act 843, the user squeezesthe release buttons on the sides of surgical device interface element450 and moves surgical device interface element 450 in the distaldirection away from the distal face of instrument manipulator assembly440, irrespective of the second preload condition being active. There isno requirement to manipulate any button on instrument manipulatorassembly 440 to remove surgical device interface element 450 under thesecond preload condition. This makes the removal of surgical deviceinterface element 450 more intuitive because only features of surgicaldevice interface element 450 are used to remove surgical deviceinterface element 450. Also, it reduces confusion because emergencyinstrument release button 482 is not used or needed for removal ofsurgical device interface element 450 under any preload condition. Afterremoval of removal of surgical device interface element 450, the userremoves the surgical drape from patient side support system 210.

Upon completion of REMOVE STERILE ADAPTER act 843, instrumentmanipulator assembly 440 is in INSERTION EXTENDED state 844. The userperforms RETRACT INSERTION act 845 to change the state of instrumentmanipulator assembly 440 from INSERTION EXTENDED state 844 to INSERTIONHOME state 846.

In RETRACT INSERTION act 845, each of the instrument manipulatorassemblies is retracted and returned to the home position by the userusing the clutch button on an instrument manipulator assembly 440 tomove that instrument manipulator assembly 440 to the home position.

With instrument manipulator assembly 440 in the home position,controller 290 performs PRELOAD RELEASE act 847 to change the state ofinstrument manipulator assembly 440 to START state 801. In one aspect,controller commands insertion assembly 431 to move instrumentmanipulator assembly 440 proximal to the home position, which asdescribed more completely below, automatically release the preload. Inanother aspect, controller 290 commands a motor to move motor pack 446to the no preload position.

FIG. 9A shows one example of instrument manipulator assembly 940 affixedto insertion assembly 931 that in turn is attached to an insertion axisbase assembly 932. Insertion axis base assembly 932 includes a motor andpower electronics to move insertion assembly 931. Instrument manipulatorassembly 940 is an example of instrument manipulator assembly 240 andinstrument manipulator assembly 440. Insertion assembly 931 is anexample of insertion assembly 331 and of insertion assembly 431.

Instrument manipulator assembly 940 includes two buttons—a clutch button944 and an emergency instrument release button, which is not visible.The emergency instrument release button is an example of emergencyinstrument release button 482. If a user depresses, i.e., activates,clutch button 944, the user can manually move instrument manipulatorassembly 940 along insertion assembly 931 in both the proximal anddistal directions. The emergency instrument release button is used torelease the preload, as described with respect to FIG. 8.

Instrument manipulator assembly 940 also includes a drive unit assembly941 and a drive output unit 942. In this aspect, drive output unit 942includes a plurality of drive output assemblies, e.g., eight driveoutput assemblies. Herein, drive output assembly 943 refers to any oneof the eight drive output assemblies. In one aspect, only six of theeight drive output assemblies are used. Drive output assembly 943includes a low backlash coupler and a drive output disk. Drive unitassembly, drive output unit 942 and drive output assembly 943 areequivalent to those described in U.S. Patent Application Publication No.US 2016/0184035 A1.

Sterile adapter assembly 250 (FIGS. 9B to 9G) includes a sterile adapterframe 951 and a sterile drape (not shown). The sterile drape is fixedlyattached to sterile adapter frame 951. Sterile adapter assembly 250 isan example of a surgical device interface element. Sterile adapter frame951 is an example of a surgical device interface element body. In moregeneral terms, a surgical device interface element is a structure thatincludes a mechanical interface between a drive interface of a drivesystem and a driven interface of an instrument, such as a surgicalinstrument or a camera instrument.

Frame 951 of sterile adapter assembly 250 has a front end 951FE, i.e., afirst end, a rear end 951RE, i.e., a second end, a first side 951S1 anda second side 951S2. Second end 951RE is sometimes referred to as anopen end of sterile adapter assembly 250 and of sterile adapter frame951, because second end 951RE is the end in which an instrument isinserted, and so is open to receive the instrument.

A first beam 955, sometimes referred to as beam 955, is movably attachedto an inside of first side 951S1 of sterile adapter frame 951 so thatwhen a distal end (a first end) of beam 955 moves in a first direction(inward), a proximal end (a second end) of beam 955 moves in a seconddirection (outward) opposite to the first direction. A second beam 956,sometimes referred to as beam 956, is movably attached to an inside ofsecond side 951S2 of sterile adapter frame 951 so that when a distal end(a first end) of beam 956 moves in a first direction (inward), aproximal end (a second end) of beam 956 moves in a second direction(outward) opposite to the first direction. The construction of beams 955and 956 is the same, and each beam has the same features.

In one aspect, beam 955 is attached to the inside of first side 951S1 bya first flexure so that when the distal end of beam 955 is moved inward,the proximal end of beam 955 moves outward. Beam 956 is attached to theinside of second side 95152 by a second flexure so that when the firstend of beam 956 is moved inward, the proximal end of beam 956 movesoutward.

In another aspect, beam 955 is pivotally attached to the inside of firstside 951S1 and includes a spring that maintains a proximal end of beam955 in an engaged position. When a force is applied to the distal end ofbeam 955, the proximal end of beam 955 pivots to a disengaged position.Similarly, beam 956 is pivotally attached to the inside of second side951S3 and includes a spring that maintains a proximal end of beam 956 inan engaged position. When a force is applied to the distal end of beam956, the proximal end of beam 955 pivots to a disengaged position.

A first hook extension 955HE1 extends in the proximal direction frombeam 955. First hook extension 955HE1 is adjacent a third end of beam955. A second hook extension 955HE2 extends in the proximal directionfrom beam 955. Second hook extension 955HE2 is adjacent a fourth end ofbeam 955, where the third end of beam 955 is removed from and does notintersect the fourth end of beam 955.

A first hook extension 956HE1 extends in the proximal direction frombeam 956. First hook extension 956HE1 is adjacent a third end of beam956. A second hook extension 956HE2 extends in the proximal directionfrom beam 956. Second hook extension 956HE2 is adjacent a fourth end ofbeam 956, where the third end of beam 956 is removed from and does notintersect the fourth end of beam 956.

Side 951S1 includes a thru-opening 959 (FIGS. 9B, 9C, and 9D) extendingfrom a proximal edge of side 951S1. A sterile adapter release button961, sometimes referred to as release button 961, is positioned inthru-opening 959. Sterile adapter release button 961 is affixed to anouter side surface of beam 955.

Second side 951S2 includes a thru-opening 960 (FIGS. 9E and 9F)extending from a proximal edge of second side 951S2. A sterile adapterrelease button 962, sometimes referred to as release button 962, ispositioned in thru-opening 960. Sterile adapter release button 962 isaffixed to an outer side surface of beam 956.

The inner side of each of beams 955 and 956 includes an instrumentinsertion skid plate 963 and 964, respectively, that terminates in aparking slot. Instrument insertion skid plate 963 is formed on the innerside of beam 955. Instrument insertion skid plate 963 extends from thefourth end of beam 955 to a parking slot 965, which is adjacent to thethird end of beam 955. Instrument insertion skid plate 964 is formed onthe inner side of beam 956. Instrument insertion skid plate 964 extendsfrom the fourth end of beam 956 to a parking slot 966, which is adjacentto the third end of beam 956.

Sterile adapter frame 951 includes a movable manipulator-instrumentinterface plate 951C, sometimes referred to as movable body 951C.Movable manipulator-instrument interface plate 951C can move in thedistal and proximal directions, e.g., in first and second directions,within sterile adapter frame 951.

Movable manipulator-instrument interface plate 951C includes areceptacle for each intermediate disk in plurality of intermediate disks953P. Moveable body 951C also includes a plurality of hard stopreceptacles 957 (FIG. 9C), which is optional.

Each intermediate disk has a cylindrical body. Each of plurality ofintermediate disks 953P is mounted in a corresponding intermediate diskreceptacle of a plurality of intermediate disk receptacles of movablebody 951C so that each intermediate disk can rotate relative to sterileadapter frame 951 and relative to movable body 951C. Thus, plurality ofintermediate disks 953P is rotatably mounted in sterile adapter frame951. Also, each intermediate disk can move distally and proximally inthe intermediate disk receptacle.

Each intermediate disk includes an intermediate driven interface on afirst side of the intermediate disk and an intermediate drive interfaceon a second side of the intermediate disk. The intermediate driveninterface is configured to mate with a drive interface on a drive outputdisk in drive output unit 942. Movable body 951C and plurality ofintermediate disks 953P are equivalent to the movable body and pluralityof intermediate disks of the sterile adapter described in PCTInternational Publication No. WO 2015/023840 A1, which was previouslyincorporated by reference.

FIGS. 10A and 10B illustrate the motions and forces required to attachsterile adapter assembly 250 to instrument manipulator assembly 1040,which is connected to insertion assembly 1031 (FIG. 10A), and todisconnect sterile adapter assembly 250 from instrument manipulatorassembly 1040 (FIG. 10B). Instrument manipulator assembly 1040 alsoincludes a drive unit assembly and a drive output unit. In this aspect,the drive output unit includes a plurality of drive output assemblies,e.g., eight drive output assemblies. Each drive output assembly includesa low backlash coupler and a drive output disk. The drive unit assembly,the drive output unit and the drive output assembly are equivalent tothose described in U.S. Patent Application Publication No. US2016/0184035 A1.

Instrument manipulator assembly 1040 is another example of instrumentmanipulator assembly 240 and instrument manipulator assembly 440.Insertion assembly 1031 is another example of insertion assembly 331 andof insertion assembly 431. Instrument manipulator assembly 1040 includestwo buttons—a clutch button 1044 and an emergency instrument releasebutton 1082. Emergency instrument release button 1082 is an example ofemergency release button 482.

Clutch button 1044 is mounted in the housing of instrument manipulatorassembly 1040. If a user depresses, i.e., activates, clutch button 1044,the user can manually move instrument manipulator assembly 1040 alonginsertion assembly 1031 in both the proximal and distal directions.

Emergency instrument release button 1082 is mounted in preload assembly1080 of instrument manipulator assembly 1040. Emergency instrumentrelease button is used to release the preload as described with respectto FIG. 8.

To mount sterile adapter assembly 250 on instrument manipulator assembly1040, a user moves sterile adapter assembly 250 in direction 1091, theproximal direction, and presses sterile adapter assembly 250 into thedistal face of instrument manipulator assembly 1040. The hook extensionsof sterile adapter assembly 250 are movable and allow a hook in each ofthe hook extensions to snap into the distal face of instrumentmanipulator assembly 1040 to securely attach sterile adapter assembly250 to instrument manipulator assembly 1040.

When sterile adapter assembly 250 is attached to instrument manipulatorassembly 1040, as illustrated in FIG. 10A, a plunger of instrumentmanipulator assembly 1040 is depressed and breaks a light beam, which inturn generates a signal that indicates to controller 290 the presence ofsterile adapter assembly 250. Alternatively, one of the other sensorsdescribed above could be used to detect the presence or absence ofsterile adapter assembly 250.

To remove sterile adapter assembly 250, the user squeezes sterileadapter release buttons 961 and 962 in inward directions using forces1092A and 1092B (inward), respectively, irrespective of whether theremay be a preload force on sterile adapter assembly 250. The inward forceon buttons 961 and 962 causes the beams to pivot which releases thehooks, including hooks 1071 and 1072 (FIG. 10C), holding sterile adapterassembly 250 to instrument manipulator assembly 1040, and so allows easyremoval of sterile adapter assembly 250. When sterile adapter assembly250 is removed from instrument manipulator assembly 1040, the plunger ofinstrument manipulator assembly 240 is no longer depressed, which inturn generates a signal that indicates to controller 290 the absence ofsterile adapter assembly 250.

FIG. 10C is an illustration of sterile adapter assembly 250 mounted ininstrument manipulator assembly 1040 with parts of sterile adapterassembly 250 and instrument manipulator assembly 1040 removed to showthe hook and hook receiver latching mechanism used to mount and holdsterile adapter assembly 250 in the distal face of instrumentmanipulator assembly 1040. In the following description of sterileadapter assembly 250 and instrument manipulator assembly 1040, withrespect to FIG. 10C, the configurations of the left and right hand sidesof sterile adapter assembly 250 and instrument manipulator assembly 1040are the same. Thus, the left hand side of FIG. 10C is described and eachreference numeral is followed by a reference numeral for thecorresponding feature of the right hand side feature of FIG. 10C toavoid replicating the description with different reference numerals forthe left and right sides of sterile adapter assembly 250 and instrumentmanipulator assembly 1040

Instrument manipulator assembly 1040 includes a first side member 1073and a second side member 1074. Side member 1073 (1074) includes a rampside surface 1075 (1076), which forms part of a hook receiver 1077(1078) of side member 1073 (1074). Hook receiver 1077 (1078) is shapedto engage a hook 1071 (1072) formed in hook extension 955HE2 (956HE2) ofbeam 955 (956), e.g. the hook receiver fits in the hook of the hookextension.

In sterile adapter assembly 250, beam 955 (956) is moveably connected toa side wall of sterile adapter assembly 250 by a flexure 1083 (1084). Inthis aspect, beam 955 (956) and flexure 1083 (1084) are formed as asingle part. In more general terms, a first end of flexure 1083 (1084)is connected to beam 955 at a location between the distal and proximalends of beam 955 (956). The location is selected to allow flexure toengage and to disengage hook 1071 (1072) formed in hook extension 955HE2(956HE2) of beam 955 (956) from hook receiver 1077 (1078) of side beam1073 (1074). A second end of flexure 1083 (1084) is connected to theside wall of sterile adapter assembly 250. In still more general terms,beam 955 (956) is pivotally connected to the sidewall at a locationbetween the distal and proximal ends of beam 955 (956)

To remove sterile adapter assembly 250 from instrument manipulatorassembly 1040, a user depresses each of release button 961, 962 towardsthe interior of sterile adapter assembly, i.e., provides a force 1092Aon button release button 961 and a force 1092B on release button 962.Forces 1092A and 1092B on release buttons 961 and 962 are applied to thedistal ends of beams 955 and 956.

The forces on the distal ends of beams 955 and 956 causes flexures 1083and 1084 to bend such that the hooks in hook extensions 955HE1 and956HE2 rotate outward away from the plane that bisects instrumentmanipulator assembly 1040 and that includes a lengthwise axis ofinstrument manipulator assembly 1040. The outward rotation of the hooksdisengages the hooks from the hook receivers, which in turn allowssterile adapter assembly 250 to move in the distal direction out ofinstrument manipulator assembly 1040.

FIG. 11A is a more detailed illustration of a prior art surgicalinstrument that can be mounted in sterile adapter assembly 250.Instrument 260, in this aspect, includes a driven interface assembly1161, a transmission unit 1165, a main tube 1167, a parallel motionmechanism 1168, a wrist joint 1169, and an end effector 1170. Wristjoint 1169 is described, for example, in U.S. Patent ApplicationPublication No. US 2003/0036748 A1 (disclosing “Surgical Tool HavingPositively Positionable Tendon-Activated Multi-Disk Wrist Joint”), whichis incorporated herein by reference. Parallel motion mechanism 1168 isdescribed, for example, in U.S. Pat. No. 7,942,868 B2 (filed Jun. 13,2007, disclosing “Surgical Instrument With Parallel Motion Mechanism”).

As shown in FIG. 11B, driven interface assembly 1161 includes aplurality of driven disks 1164P. Plurality of driven disks 1164P is anexample of driven interface elements. Driven disk 1164 is representativeof each driven disk of plurality of driven disks 1164P. Driven disk 1164is mounted on a shaft of transmission unit 1165. Also, each driven disk1164 is mounted in a receptacle in a body of driven interface assembly1161.

Mechanical components (e.g., gears, levers, gimbals, cables etc.) intransmission unit 1165 transfer torques from plurality of driven disks1164P to cables, wires, and/or cable, wire, and hypotube combinationsthat run through main tube 1167 to control movement of parallel motionmechanism 1168, wrist joint 1169, and end effector 1170. Main tube 1167,although substantially rigid, can be bent slightly between transmissionunit 1165 and entry guide 270. This bending allows the instrument bodytube bores in entry guide 270 to be spaced closer together than the sizeof the transmission units would otherwise allow. The bending isresilient so that main tube 1167 assumes its straight shape wheninstrument 260 is withdrawn from entry guide of 270 (the main tube maybe formed with a permanent bend, which would prevent instrument bodyroll).

Driven interface assembly 1161 has on each side a pair of mounting wings(1162A1, 1162B1) and (1162A2, 1162B2). Also, on each side oftransmission unit 1165 is a release button 1163A, 1163B. Mounting wing1162B2 and release button 1163B are shown in FIG. 10.

To mount instrument 260 in sterile adapter frame 951, first, mountingwings 1162A1, 1162A2 are placed on skid plates 963, 964 (FIGS. 9E, 9F,and 12 to 14) at open end 951RE of sterile adapter frame 951. FIGS. 12to 14 are cutaway views with the outer side surface of sterile adapterframe 951 and beam 956 removed.

Mounting wing 1162A1 is resting on skid plate 964 that extends from aninner sidewall of beam 956. As instrument 260 is slid on skid plate 964towards parking slot 966, which is at the opposite end of skid plate964, (FIG. 12). A top surface of first mounting wings 1162A1, 1162A2contacts the bottom edge of lip 1251A of movable body 951C, which movesmovable body 951C in the proximal direction (FIGS. 12 and 13). Theproximal motion of movable body 951C depresses plunger 1246 ofinstrument manipulator assembly 1040 in the proximal direction, which inturn generates a signal to controller 290 that instrument 260 is beingloaded unto sterile adapter assembly 250.

When mounting wing 1162A1 reaches parking slot 966 (FIG. 14), the topsurface of first mounting wings 1162A1, 1162A2 no longer contacts thebottom edge of lip 1251A of movable body 951C. Consequently, the preloadforce on movable body 951C moves body 951C in the distal direction (FIG.13) and locks first mounting wing 1162A1 in place. When first mountingwing 1162A1 reaches the end of sterile adapter frame 951, secondmounting wing 1162B1 rests on a flat portion of skid plate 964 near theopen end of sterile adapter frame 951 (FIG. 14).

Each intermediate disk 953 in sterile adapter frame 951 is being pushedaxially in the distal direction by the preload force on the plurality ofdrive output disks of the instrument manipulator assembly. Thus, asinstrument 260 is mounted in sterile adapter frame 951, plurality ofintermediate disks 953P transfers the first preload force to movablebody 951C so that the preload force is applied to mounting wing 1162A1.This preload force is selected so that instrument 260 can be easily slidinto sterile adapter frame 951, and so that a small preload force ismaintained on all the disks.

When instrument 260 is mounted in sterile adapter assembly 250,instrument manipulator assembly 1040 detects the presence of instrument260 and sends a signal to controller 290 that indicates the presence ofinstrument 260. In response to the signal, controller 290 in system 200sends the signal to instrument manipulator assembly 1040 to rotate eachdrive output disk of the plurality of drive output disks of theinstrument manipulator assembly.

As explained more completely in U.S. Patent Application Publication No.US 2016/0184037 A1, each drive output assembly 943 in drive output unit942 is spring-loaded and is automatically positioned so that a preloadforce is exerted on each drive output disk after sterile adapterassembly 250 is mounted on instrument manipulator assembly 1040. Thepreload force pushes against the drive output disk and against acorresponding intermediate driven interface of intermediate disk 953 insterile adapter frame 951.

However, when instrument 260 is first mounted on sterile adapterassembly 250, the elements of the intermediate drive interface ofintermediate disk 953 may not be aligned with corresponding elements ofdriven interface 1180 on driven disk 1164. If the elements of the twodisks 953 and 1164 are not aligned, the two disks are partially coupled,but the two disks are not mated to each other. Thus, a disk stackincluding the drive disk, the intermediate disk, and the driven disk arepartially coupled. To mate the disks, INSTRUMENT ENGAGEMENT SEQUENCE act836 is performed.

In one aspect, each of sterile adapter frame 951, movable body 951C, andthe plurality of intermediate disks 653P are made by injection molding.Suitable materials for sterile adapter frame 951, movable body 951C, andplurality of intermediate disks 953P include polycarbonate,polyphenlysulfone (PPSU), polyethylenimine (PEI), etc.

Beams 955 and 956 of sterile adapter assembly 250 are included in amechanical instrument removal lockout, which is activated by mountinginstrument 260 in sterile adapter assembly 250. Specifically, if theproximal ends of beams 955 and 956 cannot move inward by pressingrelease buttons 961 and 962, the hooks of sterile adapter assembly 250cannot be disengaged from the hook receivers of instrument manipulatorassembly 1040. When instrument 260 is mounted in sterile adapterassembly 250, the body of instrument prevents inward movement of beams955 and 956, and so instrument 260 is said to activate the mechanicalinstrument lock out, which are beams 955 and 956.

More specifically, as shown in FIG. 15, distance 1501 between beams 955and 956 is selected based on the size of the body of instrument 260.Distance 1501 is selected so that when instrument 260 is mounted insterile adapter assembly 250, any movement of the proximal ends of beams955 and 956 is not sufficient to disengage the hooks of sterile adapterassembly 250 from the hook receivers of instrument manipulator assembly1040. Thus, to prevent accidental release of sterile adapter assembly250, the body of instrument 260 physically blocks movement of beams 955and 946, thereby preventing sterile adapter assembly 250 removal wheninstrument 260 is present. This lock-out is independent of any preloadforce that may be present.

FIG. 16 is a more detailed illustration of one aspect of insertionassembly 331. Insertion assembly 331 includes a frame 1610, amid-carriage 1620, and a distal carriage 1630. Mid-carriage 1620 rideson a ball screw 1611 in frame 1610. In one aspect, ball screw 1611 has a6 mm pitch, and so mid-carriage 1620 is back drivable. Mid-carriage 1620includes metal belts 1621 that drive distal carriage 1630. Distalcarriage 1630 is attached to an instrument manipulator assembly housingof instrument manipulator assembly 240. Distal carriage 1630 moves twiceas far as mid-carriage 1620, in one aspect.

FIGS. 17A and 17B illustrate preload assembly 1080 and operation ofpreload assembly 1080. The construction and operation of preloadassemblies 480 and 980 are the same as illustrated in FIGS. 17A and 17B,in one aspect. For ease of illustration, instrument 260, sterile adapterassembly 250, the housing of instrument manipulator assembly 1040, andinsertion assembly 331 are not shown in FIGS. 17A and 17B. When preloadassembly 1080 is in the configuration shown in FIG. 17A, the distal endof instrument 260 is, for example, positioned at an entry to a channelin entry guide 270. Similarly, in FIGS. 18A to 18E and 19A to 19C, onlythe elements necessary to understand the preload assembly areillustrated. The actual configuration associated with FIGS. 17A, 17B,18A to 18E and 19A to 18C includes all the elements shown and describedwith respect to FIGS. 9A to 9E, 10A to 10C, 11A, and 11B.

Prior to considering the operation of preload assembly 1080, theelements in preload assembly 1080 are described. Unlike the preloadassembly described in U.S. Patent Application Publication No. US2016/0184036 A1, the preload supplied by preload assembly 980 can bereleased automatically by controller 290 and can be released manually bya user. The preload supplied by the preload assembly described in U.S.Patent Application Publication No. US 2016/0184036 A1 could only bereleased manually by the user.

In FIGS. 17A, 17B, 18A to 18E, and 19A to 19C, a preload track 1725 ismounted on mid-carriage 1620. A valley is located at a proximal end ofpreload track 1725. A ramp 1725R in preload track 1725 connects thevalley to a flat portion of preload track 1725. A preload engagementridge 1726 extends from preload track 1725 distal to ramp 1725R. Adescription of a preload track suitable for use as preload track 1725 ispresented in U.S. Patent Application Publication No. US 2016/0184036 A1,which is incorporated herein by reference in its entirety.

A wheel 1783W is rotatably attached to a first end of a cam followerassembly 1783. Wheel 1783W rides on preload track 1725. (In some ofFIGS. 17A, 17B, 18A to 18E, and 19A to 19C, wheel 1783W appears to bedisplaced from preload track 1725. This is for ease of illustrationonly. In all instances shown in FIGS. 17A, 17B, 18A to 18E and 19A to19C, wheel 1783W is in contact with and rides on preload track 1725.)

Cam follower assembly 1783 pivots about pivot pin 1784, a first pivotpin. Cam follower assembly 1783 is rotatably connected to a first end ofan arm 1782 in preload assembly 1080. A first end, e.g., a distal end,of arm 1782 is connected to a motor pack bracket 1781. A description ofa cam follower assembly suitable for use as cam follower assembly 1783is presented in U.S. Patent Application Publication No. US 2016/0184036A1.

Motor pack bracket 1781 is affixed to a motor pack 1746. Thus, arm 1782is coupled to motor pack 1746. As indicated above, the instrumentmanipulator assembly housing is affixed to distal carriage 1630. Oneexample of motor pack 1746 is presented in U.S. Patent ApplicationPublication No. US 2016/0184036 A1.

A second end, a proximal end, of preload engagement arm 1786 isrotatably coupled to a pivot pin 1784. Pivot pin 1784 is slideablycoupled to the housing of instrument manipulator assembly 1040

A rolling pin 1786P is mounted in a first end, a distal end, of preloadengagement arm 1786. Proximal to rolling pin 1786P in the first end ofpreload engagement arm 1786 is a preload engagement surface 1786S,sometimes referred to as surface 1786S. In this aspect, preloadengagement surface 1786S is perpendicular to the flat portion of preloadtrack 1725. Preload engagement arm 1786 is coupled to a linear rail1787. A description of a preload engagement arm and linear rail suitablefor use as preload engagement arm 1786 and linear rail 1787 is presentedin U.S. Patent Application Publication No. US 2016/0184036 A1.

In this aspect, preload engage/disengage arm 1785, sometimes referred toas arm 1785, is a T-shaped structure having a cross-bar and a leg. TheT-shaped structure is rotated ninety degrees clockwise with respect tothe vertical so that the leg of the T-shaped structure is horizontal, orin more general terms is perpendicular to the cross-bar. The use of aT-shape structure is optional. Any shape of preload engage/disengage arm1785 that can perform the acts described below can be used.

The cross-bar of preload engage/disengage arm 1785 functions as a lever,and so is sometimes referred to as a lever or a lever portion of preloadengage/disengage arm 1785. A hook on a second end, a proximal end, ofthe cross-bar of preload engage/disengage arm 1785 is engaged withrolling pin 1786P in the second end of arm 1785 when a preload isenabled, and is disengaged with rolling pin 1786P when the preload isdisabled. Emergency instrument release button 1082 is coupled to, e.g.,is in contact with, a first end, a distal end, of the cross-bar ofpreload engage/disengage arm 1785. Emergency instrument release button1082 is an example of emergency instrument release button 482 andemergency instrument release button 982.

Between the first and second ends of the cross-bar of preloadengage/disengage arm 1785, preload engage/disengage arm 1785 isrotatably mounted on another pivot pin 1788, a second pivot pin, whichfunctions as a fulcrum for the lever action of preload engage/disengagearm 1785. The leg of the T-shaped structure extends from the leverportion of arm 1785 so that pivot pin 1788 is centered with respect tothe leg of the T-shaped structure. Thus, the leg of preloadengage/disengage arm 1785 has a first end and a second end, with thefirst end connected to the cross-bar of preload engage/disengage arm1785.

A torsional spring 1789 (FIG. 17C) concentric with pivot pin 1788 exertsa counter-clockwise torque on preload engage/disengage arm 1785(counter-clockwise relative to FIGS. 17A, 17B, 18A to 18E, and 19A to19C). Torsional spring 1789 provides a force on preload engage/disengagearm 1785, which moves the hook of preload engage/disengage arm 1785 awayfrom an axis extending through pivot pin 1784 and pivot pin 1788. Theaxis extending through pivot pin 1784 and pivot pin 1788 isperpendicular to a lengthwise axis of pivot pin 1784 and a lengthwiseaxis of pivot pin 1788. Torsional spring 1789 rotates preloadengage/disengage arm 1785 in a preload disengage direction, which isnecessary to keep preload engage/disengage arm 1785 in the releasedposition that is shown in FIGS. 18A 18B, 18C, 19B, and 19C.

In one aspect, with respect to emergency instrument release button 1082,the lever portion of preload engage/disengage arm 1785 is a Class 1lever because the fulcrum is between the effort (the forces supplied byemergency instrument release button 1082) and the load (the couplingbetween the hook and rolling pin 1786P). While in this example, preloadengage/disengage arm 1785 is implemented as a Class 1 lever, this isillustrative only and is not intended to be limiting. In other aspects,a Class 2 lever or a Class 3 lever could be used. For a Class 2 lever,the load is between the fulcrum and the effort, and for a Class 3 lever,the effort is between the fulcrum and the load.

The second end of the leg of preload engage/disengage arm 1785 isconnected to a second end of a link 1723. A first end of link 1723 isconnected to an electric actuator, which is this example is implementedas a solenoid 1720 having a plunger 1721. In this aspect, the first endof link 1723 is connected to plunger 1721. The electric actuator isconnected to controller 290. In response to commands from controller290, the electric actuator is enabled and disabled.

Emergency instrument release button 1082, preload engage/disengage arm1785, preload engagement arm 1786, torsional spring 1789, the electricactuator and link 1723 form a preload engage/disengage mechanism ofpreload assembly 1080. Hence, both the preload engage/disengagemechanism and preload assembly 1080 are mechanical structures that acoupled to a controller.

Preload engage/disengage arm 1785 is rotatably coupled to second pivotpin 1788. Preload engage/disengage arm 1785 is couplable to anddecouplable from rolling pin 1786P of preload engagement arm 1786.Torsional spring 1789 mounted on second pivot pin 1788 and is coupled topreload engage/disengage arm 1785. Torsional spring 1789 is configuredto provide a torque on preload engage/disengage arm 1785 to hold preloadengage/disengage arm 1785 in a disengaged position from rolling pin1786P. See FIGS. 18A and 18B.

Initially, as shown in FIG. 17A, cam follower assembly 1783 in preloadassembly 1080 is positioned in a valley in a preload track 1725 onmid-carriage 1620, e.g., is positioned at a first location—a homelocation—on preload track 1725. At the first location, a light preloadspring in each drive output assembly of motor pack 1746 has beencompressed, and the first preload force is applied to each disk in thedisk stack (See FIG. 4E). As surgical device assembly 300 is moveddistally a distance Zload by insertion assembly 331 from the firstlocation to a second location the instrument manipulator assemblyhousing is moved distance Zload.

Pivot pin 1784, on which cam follower assembly 1783 is rotatablymounted, is coupled to instrument manipulator assembly housing ofinstrument manipulator assembly 1040. Thus, as insertion assembly 331moves the instrument manipulator assembly housing distally a distanceZload, pivot pin 1784 moves cam follower assembly 1783 the same distanceZload. In one aspect, distance Zload is 3.85 inches.

As described above, wheel 1783W is rotatably attached to a first end ofcam follower assembly 1783, and wheel 1783W rides on preload track 1725.Thus, as cam follower assembly 1783 moves distally, wheel 1783W followsthe contour of preload track 1725. However the distance between preloadtrack 1725 and pivot pin 1784 diminishes as cam follower assembly 1783moves distally. Consequently, as cam follower assembly 1783 rides upramp 1725R in preload track 1725, cam follower assembly 1783 rotatesfrom a first position illustrated in FIG. 17A to a second position asillustrated in FIG. 17B and moves motor pack 1746 a distance that isgreater than the distance traveled by the instrument manipulatorassembly housing. Thus, the rotation of cam follower assembly 1783displaces motor pack 1746 a predetermined distance A distally relativeto the instrument manipulator assembly housing.

Two acts are performed by cam follower assembly 1783 as cam followerassembly 1783 travels along preload track 1725. As cam follower assembly1783 moves up ramp 1725R and rotates, the rotation of cam followerassembly 1783 pushes motor pack distally a distance greater thandistance Zload, e.g., motor pack 1746 moves a distance (Zload+Δ). Inaddition, as cam follower assembly 1783 moves up ramp 1725R, camfollower assembly 1783 transfers a force to motor pack 1746, which inturn compresses both the light preload spring and the high preloadspring in each drive output assembly so that a second preload force—thehigh preload force—is asserted on each drive output disk of instrumentmanipulator assembly 1040. Of course, this is true only when aninstrument has been installed, because otherwise the springs do notcompress.

FIGS. 18A to 18E are illustrations of one implementation of actsperformed in the automatic setting of the preload by preload assembly1080. The operation of preload assemblies 480 and 980 is the same asillustrated in FIGS. 18A to 18E, in one aspect.

When sterile adapter assembly 250 is mounted on instrument manipulatorassembly 1040 in INSTALL STERILE ADAPTER act 817, instrument manipulatorassembly 1040 sends a signal to controller 290 indicating the presenceof sterile adapter assembly 250.

When a user depresses clutch button 1044 and moves instrumentmanipulator assembly 1040 proximally, the instrument manipulatorassembly housing moves proximally twice as fast as preload engagementridge 1726 on preload track 1725. This is because distal carriage 1630to which instrument manipulator assembly 1040 is attached moves twice asfar as mid carriage 1620 to which preload track 1725 is attached. Inthis aspect, preload engagement ridge 1726 extends from a distal portionof preload track 1725.

Initially, when instrument manipulator assembly 1040 is at the homeposition, there is a gap 1801 between preload engagement ridge 1726 onpreload track 1725 and preload engagement surface 1786S of preloadengagement arm 1786. Controller 290 commands the insertion assembly tomove the instrument manipulator assembly in the proximal direction fromthe home position. As the instrument manipulator assembly housing movesproximally, preload engagement ridge 1726 moves proximally at half thespeed of preload engagement arm 1786 and the instrument manipulatorassembly housing and insertion assembly 331 shortens. Thus, mid-carriage1620 and distal carriage 1630 move relatively closer together closinggap 1801 between preload engagement ridge 1726 on preload track 1725 andpreload engagement surface 1786S of preload engagement arm 1786.

As gap 1801 closes (FIG. 18B), surface 1786S of preload engagement arm1786 engages preload engagement ridge 1726 on preload track 1725. Whilethe proximal motion of preload engagement arm 1786 is constrained tomove proximally with preload track 1725, instrument manipulator assembly1040 continues to move proximally with distal carriage 1630 and linearrail 1787 slides relative to the rail in instrument manipulator housing.Arm 1782 holds motor pack 1746 in place as the instrument manipulatorhousing continues to move proximally which extends the motor pack returnspring.

When instrument manipulator assembly 1040 is a predetermined distanceproximal to the home position, e.g., 2 mm, the hook on a second end ofthe lever included in preload engage/disengage arm 1785 is proximal torolling pin 1786P in the first end of preload engagement arm 1786 (FIG.18C). However, torsional spring 1789 about pivot pin 1788 preventspreload engage/disengage arm 1785 from rotating clockwise to engagerolling pin 1786P.

When instrument manipulator assembly reaches the fully withdrawnposition (a third position), controller 290 fires solenoid 1720, whichmoves plunger 1721 in the proximal direction. The motion of plunger 1721in the proximal direction moves link 1723 in the proximal direction,which in turn causes the hook on preload engage/disengage arm 1785 torotate clockwise until the hook on preload engage/disengage arm 1785engages rolling pin 1786P (FIG. 18D).

After the engagement of the hook on preload engage/disengage arm 1785 onrolling pin 1786P, controller 290 causes instrument manipulator assembly1040 to move distally to the home position so that there is a gapbetween preload engagement ridge 1726 on preload track 1725 and preloadengagement surface 1786S of preload engagement arm 1786 (FIG. 18E). Inthis position, a motor pack return spring in instrument manipulatorassembly pulls motor pack 1746 in the distal direction. The forcesupplied by the motor pack return spring is sufficient to keep the hookof preload engage/disengage arm 1785 engaged with rolling pin 1786P.This puts the hook under tension so that torsional spring 1789 cannotrotate preload engage/disengage arm 1785 in the counter-clockwisedirection. Consequently, controller 290 removes the fire command tosolenoid 1720. As illustrated in FIGS. 18A to 18E, instrumentmanipulator assembly 1040 is automatically configured under the controlof controller 290 to set the first preload on motor pack 1746.

FIGS. 19A to 19C are illustrations of one implementation of actsperformed in the automatic releasing of the preload by preload assembly1080, in one aspect. The operation of preload assemblies 480 and 980 isthe same as illustrated in FIGS. 19A to 19C.

As instrument manipulator assembly 1040 and preload assembly 1080 aremoved proximally, cam follower assembly 1783 (FIG. 17B) movesproximally, wheel 1783W follows the contour of preload track 1725.However the distance between preload track 1725 and pivot pin 1784increases as cam follower assembly 1783 moves proximally. Consequently,as cam follower assembly 1783 rides down ramp 1725R in preload track1725, cam follower assembly 1783 rotates from the second positionillustrated in FIG. 17B to the position as illustrated in FIG. 17A. Thisreleases the second preload so that when preload assembly 1080 is at thehome position, as shown if FIG. 19A, only the first preload force isactive. This also withdraws the hard stops from sterile adapter assembly250 so that instrument 260 can be removed, because the movablemanipulator-instrument interface plate can be moved proximally when thehard stops are withdrawn.

With respect to FIG. 19A, controller 290 activates the motor that movesinstrument manipulator assembly 1040 proximally. The instrumentmanipulator assembly housing moves proximally twice as fast as preloadengagement ridge 1726 on preload track 1725. This is because distalcarriage 1630 to which instrument manipulator assembly 1040 is attachedmoves twice as far as mid carriage 1620 to which preload track 1725 isattached.

Initially, there is a gap between preload engagement ridge 1726 onpreload track 1725 and preload engagement surface 1786S of preloadengagement arm 1786 (FIG. 19A). As the instrument manipulator assemblyhousing moves proximally, preload engagement ridge 1726 moves proximallyat half the speed of preload engagement arm 1786 and the instrumentmanipulator assembly housing and insertion assembly 331 shortens. Thus,mid-carriage 1620 and distal carriage 1630 move relatively closertogether closing the gap between preload engagement ridge 1726 onpreload track 1725 and preload engagement surface 1786S of preloadengagement arm 1786.

As the gap closes (FIG. 19B), surface 1786S of preload engagement arm1786 engages preload engagement ridge 1726 on preload track 1725. Whilethe proximal motion of preload engagement arm 1786 is constrained tomove proximally with preload track 1725, instrument manipulator assembly1040 continues to move proximally with distal carriage 1630 and linearrail 1787 slides relative to the rail in instrument manipulator housing.

When instrument manipulator assembly 1040 is a predetermined distanceproximal to the home position, e.g., 2 mm, the hook on a second end ofthe lever included in preload engage/disengage arm 1785 is proximal torolling pin 1786P in the first end of preload engagement arm 1786 (FIG.18C). Since solenoid 1720 is not active, torsional spring 1789 aboutpivot pin 1788 rotates preload engage/disengage arm 1785counter-clockwise to disengage the hook from rolling pin 1786P.

After the dis-engagement of the hook on preload engage/disengage arm1785 to rolling pin 1786P, controller 290 causes instrument manipulatorassembly 1040 to move distally to the home position. Since the hook onpreload engage/disengage arm 1785 is disengaged from preload engagementarm 1786, there no force on motor pack 1746 in the distal direction, Themotor pack is not displaced distally relative to the instrumentmanipulator housing, and so no preload force is present as instrumentmanipulator assembly 1040 is moved distally. Thus, as illustrated inFIGS. 19A to 19C, instrument manipulator assembly 1040 is automaticallyconfigured under the control of controller 290 to reset the firstpreload on motor pack 1746 and to prevent application of any preloadforce as instrument manipulator assembly 1040 is moved distally from afully withdrawn position to and beyond the home position.

If insertion assembly 331 jams in the extended position, the highpreload force must be released so that instrument 260 can be removed. Toremove instrument 260, a user pushes emergency instrument release button1082 (FIG. 10A). In response to the force provided by the user,emergency instrument release button 1082 applies a force to the firstend of preload engage/disengage arm 1785. The force on the first endpreload engage/disengage arm 1785 causes preload engage/disengage arm1785 to rotate about pivot pin 1788 and disengage the hook on the secondend of preload engage/disengage arm 1785 from rolling pin 1786P that ismounted in the second end of preload engagement arm 1786.

Recall that the motor pack return spring is mounted between instrumentmanipulator assembly housing and motor pack 1746 and is stretched whenthe high preload force is applied. Consequently, when preloadengage/disengage arm 1785 disengages from preload engagement arm 1786,the motor pack return spring retracts motor pack 1746 to a fullywithdrawn position.

At the fully withdrawn position, there is no preload force, and so thedrive output disk is disengaged from the intermediate disk. In addition,the plurality of hard stops is withdrawn so that both instrument sterileadapter assembly 250 and instrument 260 can be dismounted. If the distalend of instrument 260 is not straight, as a person withdraws theinstrument, the cannula forces the distal end of instrument 260 tostraighten because the disk stack without the preload force and withoutdrive output disk engaged is back drivable.

FIG. 20A shows an instrument manipulator assembly 2040 affixed to aninsertion assembly 2031 (also called insertion mechanism 2031).Instrument manipulator assembly 2040 is another example of each ofinstrument manipulator assemblies 240, 440, and 1040. Insertion assembly2031 is an example of insertion assembly 331. A position of instrumentmanipulator assembly 2040 is determined by insertion assembly 2031 andvaries from a home position to a fully extended position. In the fullyextended position, insertion assembly 2031 is fully extended.

Instrument manipulator assembly housing 2048, sometimes referred to ashousing 2048, is fixedly attached to a distal end of insertion assembly2031, and so instrument manipulator assembly housing 2048 moves withmovement of insertion assembly 2031 from the home position to the fullyextended position.

A motor pack 2046 within instrument manipulator assembly housing 2048can move on rail 2039. Motor pack 2046 can move in the distal andproximal directions relative to instrument manipulator assembly housing2048. Motor pack 2046 is coupled to instrument manipulator assemblyhousing 2048 by a motor pack return spring 2047, sometimes referred toas return spring 2047. The elements included with motor pack 2046 arethe same as the elements described above with respect to motor pack 446,in one aspect. Motor pack return spring 2047 is equivalent to motor packreturn spring 447.

Preload assembly 2080 is mounted to instrument manipulator assemblyhousing 2048, and so moves with housing 2048. Preload assembly 2080 isconnected to motor pack 2046 by an arm 2088. Preload assembly 2080includes an emergency instrument release button 2082.

Unlike motor pack 446 that is movably coupled to insertion assembly 431by preload assembly 480, motor pack 2046 is not movably coupled toinsertion assembly 2031 by preload assembly 2080. However, preloadassembly 2080 has the capability to move motor pack 2046 relative tohousing 2048 irrespective of the position of instrument manipulatorassembly 2040 relative to the home position. Thus, in contrast to theaspect in FIGS. 18A to 18E and 19A to 19C, where as the instrumentmanipulator assembly moved from the home position, the preload assemblymoved along the track and increased the preload from the first preloadto the second preload. Here, preload assembly 2080 is under the directcontrol of controller 290, e.g., a motor controller in controller 290,and so the preload can be increased, or decreased irrespective of theposition of instrument manipulator assembly 2040 relative to the homeposition, and irrespective of whether instrument manipulator assembly2040 is being moved by insertion assembly 2031 or is stationary.

When no preload is desired and when motor pack 2046 is not displaced inthe distal direction relative to instrument manipulator assembly housing2048, controller 290 does not take any action. (Note that the preloaddesired is determined, in one aspect, by the state of instrumentmanipulator assembly 2040, as described above with respect to FIG. 8.)In this case, motor pack 2046 is at a no preload position 2032 relativeto instrument manipulator housing 2048 irrespective of where between thehome position and the fully extended position instrument manipulatorassembly is positioned.

Movement of instrument manipulator assembly 2040 alone from the homeposition to the fully extended position, or from the fully withdrawnposition to the home position does not change the preload. The preloadchanges only if controller 290 sends a command directly to preloadassembly 2080 to make a change, or if emergency instrument releasebutton 2082 is activated. With motor pack 2046 at no preload position2032, if a sterile adapter assembly were mounted in the distal face ofinstrument manipulator assembly 2040 there would be no preload force onthe intermediate disks of the sterile adapter assembly.

If a low preload is desired and if motor pack 2046 is not displaced inthe distal direction relative to instrument manipulator assembly housing2048, i.e., motor pack is at no preload position 2032, controller 290commands preload assembly 2080 to move arm 2088 in the distal directionto move motor pack 2046 to low preload position 2033. As motor pack 2046is moved distally relative to instrument manipulator housing 2048, motorpack return spring 2047 is extended.

If a sterile adapter assembly were mounted in the distal face ofinstrument manipulator assembly 2040 with motor pack 2046 at low preloadposition 2033, there would be a low preload force, e.g., a first preloadforce, on the intermediate disks of the sterile adapter assembly. In theexamples of FIGS. 20A and 20B, the preload force was increased bycontroller 290, but instrument manipulator assembly 2040 was not movedby insertion assembly 2031. Alternatively, the preload force can beincreased by controller 290 as instrument manipulator assembly is movedby insertion assembly 290. If emergency instrument release button 2082is activated when motor pack 2046 is at low preload position 2033, thepreload mechanism in preload assembly 2080 is disengaged, and motor packreturn spring 2047 retracts motor pack 2046 in the proximal direction tono preload position 2032.

If a low preload is desired and if motor pack 2046 is at high preloadposition 2034 relative to instrument manipulator assembly housing 2048,i.e., motor pack is at high preload position 2034, controller 290commands preload assembly 2080 to move arm 2088 in the proximaldirection to move motor pack 2046 to low preload position 2033. As motorpack 2046 is moved proximally relative to instrument manipulator housing2048, motor pack return spring 2047 is contracted. Again, this could bedone without or with insertion mechanism moving instrument manipulatorassembly 2040, because the preload force supplied by preload assembly2080 can be changed independent of the position of preload assemblyrelative to the home position, and independent of whether insertionassembly 2031 is moving instrument manipulator assembly 2040. Change ofthe preload is not dependent on a command from controller 290 toinsertion mechanism 2031 to change the position of instrumentmanipulator assembly 2040, which is different from the embodimentsdescribed with respect to FIGS. 19A to 19C.

The control of the preload by controller 290 is irrespective of controlof insertion assembly 2031 on which instrument manipulator assembly 2040is mounted. This means that unlike the previously described aspects, acommand by controller 290 to insertion mechanism 2031 to change theposition of instrument manipulator assembly 2040 cannot change thepreload. Rather, controller 290 commands preload assembly 2080 directlyto change the preload. It is recognized that controller 290 may commandpreload assembly 2080 to change the preload based on a position ofinstrument manipulator assembly 2040. Thus, a command to preloadassembly 2080 may be coupled to a command to insertion assembly 2031,but the command to insertion assembly 2031 cannot change the preload inthis aspect, and so the control of the preload by controller 290 is saidto be irrespective of control of insertion assembly 2031 on whichinstrument manipulator assembly 2040 is mounted.

If no preload is desired and if motor pack 2046 is at low preloadposition 2033 relative to instrument manipulator assembly housing 2048,i.e., motor pack 2046 is at low preload position 2033, controller 290commands preload assembly 2080 to move arm 2088 in the proximaldirection to move motor pack 2046 to no preload position 2032. As motorpack 2046 is moved proximally relative to instrument manipulator housing2048, motor pack return spring 2047 is contracted. Yet again, this couldbe done without or with insertion mechanism 2031 moving instrumentmanipulator assembly 2040, because the preload force supplied by preloadassembly 2080 can be changed by controller 290 independent of theposition of preload assembly 2080 relative to insertion assembly 2031and independent of the position of instrument manipulator assembly 2040relative to the home position. Of course, this also can be done asinsertion assembly 2031 moves instrument manipulator assembly 2040.

If a high preload is desired, controller 290 commands preload assembly2080 to move arm 2088 in the distal direction to move motor pack 2046 tohigh preload position 2034. As motor pack 2046 is moved distallyrelative to instrument manipulator housing 2048, motor pack returnspring 2047 is extended.

If a sterile adapter assembly were mounted in the distal face ofinstrument manipulator assembly 2040 with motor pack 2046 at highpreload position 2034, there would be a high preload force, e.g., asecond preload force, on the intermediate disks of the sterile adapterassembly. If emergency instrument release button 2082 is activated whenmotor pack 2046 is at high preload position 2034, the preload mechanismin preload assembly 2080 is disengaged, and motor pack return spring2047 retracts motor pack 2046 in the proximal direction to no preloadposition 2032, which removes the high preload force.

If motor pack 2046 is high preload position 2033 relative to instrumentmanipulator assembly housing 2048, controller 290 can command preloadassembly 2080 to move motor pack 2046 proximally to either low preloadposition 2033 or to no preload position 2032. In the examples of FIGS.20A, 20B, and 20C, the preload force was increased by controller 290,but insertion assembly 2031 did not move instrument manipulator assembly2040. The preload force could also be changed by controller 290 in eachof these examples as insertion assembly 2031 moves instrumentmanipulator assembly 2040.

In the examples discussed below with respect to FIGS. 21A to 21C and inthe examples illustrated in FIGS. 4A to 4G, the mechanical instrumentremoval lockout—the prevention of the movable body in the sterileadapter assembly from moving proximally—is activated by moving the motorpack in the instrument manipulator assembly. In another aspectillustrated in FIGS. 21D and 21E, the mechanic instrument removallockout is independent of movement of any part of instrument manipulatorassembly 2040. In this aspect, a mechanical instrument removal lockoutassembly 2090 is mounted to housing 2048 of instrument manipulatorassembly 2040. Mechanical instrument removal lockout assembly 2090 isconnected to a lockout arm 2091, sometimes referred to as arm 2091,which includes a plurality of stops on the proximal end. The pluralityof stops is optional and is used an example for interfacing with thesterile adapter assemblies described previously. In more general terms,a distal face of arm 2091 could interface with a proximal face of amovable body of a sterile adapter assembly, for example. An emergencyinstrument release button 2082A is shared between preload assembly 2080and mechanical instrument removal lockout assembly 2090, in this aspect.A lockout return spring 2047A is connected between a proximal end oflockout arm 2091 and housing 2048, in one aspect.

A sterile adapter assembly 2050 (FIG. 20D) is mounted in the distal faceof instrument manipulator assembly 2040. Sterile adapter assembly 2050includes a moveable manipulator-instrument interface plate 2051C,sometimes referred to as movable body 2051C, which can move in theproximal and distal directions relative to a frame of sterile adapterassembly 2050. Sterile adapter assembly 250 is an example of sterileadapter assembly 2050, and so sterile adapter assembly 2050 is notdescribed in further detail.

As explained previously, when an instrument is mounted or removed fromsterile adapter assembly 2050, movable body 2051C is moved in theproximal direction. To prevent removal of the instrument, movable body2051C is prevented from moving in the proximal direction by mechanicalinstrument removal lockout assembly 2090 by locking movable body 2051Cin place.

An optional mechanical instrument removal lockout assembly 2090 (FIG.20D) is under the direct control of controller 290, e.g., a motorcontroller in controller 290. The mechanical instrument removal lockoutcan be activated or deactivated irrespective of the position ofinstrument manipulator assembly 2040 relative to the home position,irrespective of whether instrument manipulator assembly 2040 is beingmoved by insertion assembly 2031 or is stationary, and irrespective ofthe position of motor pack 2046 relative to housing 2048. The motion ofarm 2091 is independent of motion of instrument manipulator assembly2040 and is independent of motion of motor pack 2046. Arm 2091 movesonly when controller 290 commands mechanical instrument removal lockoutassembly 2090 to move arm 2091, or when arm 2091 is an extendedposition, and emergency instrument release button 2082A is activated bya user.

In this aspect, arm 2091 has a proximal position, illustrated in FIG.20D, and a distal position illustrated in FIG. 20E. In the proximalposition, a second position, no part of arm 2091 is in contact withmoveable body 2051C of sterile adapter assembly 2050. If mechanicalinstrument removal lockout assembly 2090 receives an engage lockoutcommand from controller 290, mechanical instrument removal lockoutassembly 2090 moves arm 2091 to the distal position (FIG. 20E), whichlocks movable body 2051C in a distal position in sterile adapterassembly 2050. With moveable body 2051C locked in the distal position,an instrument mounted in sterile adapter assembly cannot be removed.

As arm 2091 moves to the distal position, return spring 2047A isextended. If emergency instrument release button 2082A is activated, arm2091 is disengaged from mechanical instrument removal lockout assembly2090, and return spring 2047A pulls arm 2091 to its proximal position(FIG. 20D). Thus, movable body 2051C can be moved in the proximaldirection, and the instrument can be removed.

Alternatively, controller 290 can send a disengage lockout command tomechanical instrument removal lockout assembly 2090. When mechanicalinstrument removal lockout assembly 2090 receives the disengage lockoutcommand from controller 290, mechanical instrument removal lockoutassembly 2090 moves arm 2091 form the distal position in FIG. 20E to theproximal position in FIG. 20D, which unlocks movable body 2051C insterile adapter assembly 2050 and permits movement of movable body2051C.

FIGS. 21A to 21C are examples for one aspect of instrument manipulatorassembly 2040 and preload assembly 2080 in FIGS. 20A to 20C. Elements ininstrument manipulator assembly 2040 in FIGS. 21A to 21C with the samereference numeral as in FIG. 4A are elements equivalent to those in FIG.4A, and so the description of the elements with respect to FIG. 4A isnot repeated here.

In this aspect, preload assembly 2080 includes a motor 2181, e.g., aservomotor, that is connected to controller 290. Motor 2181 is mountedto housing 2048. Motor 2181 drives a screw 2183. A nut 2184 is mountedon screw 2183 and moves proximally or distally as motor 2181 rotatesscrew 2183. In one aspect, screw 2183 is a threaded shaft of motor 2181.The rotation of the shaft of motor 2181, and hence the distal orproximal movement of nut 2184, is controlled by controller 290. Themotor, screw, and nut combination is an example of a movable assemblywhose position along an axis is directly controlled by controller 290.

A preload tab 2184T extends from an outer side surface of nut 2184adjacent to a distal end of nut 2184. Preload tab 2184T has a firstplanar surface on a distal face and a second planar surface on aproximal face. The first planar surface extends further from the outerside surface of nut 2184 than does the second planar surface. Thus, asurface joining first planar surface to the second planar surface is aramped surface.

A preload release lever 2186 is mounted on a pivot pin 2187. A torsionalspring is mounted around the pivot pin and attached to preload releaselever 2186 to maintain preload release lever 2186 in a preload engagedposition if emergency instrument release button 2082 is not engaged.Pivot pin 2187 is mounted on arm 2088 that is connected to motor pack2046. In this example, arm 2088 moves proximally and distally relativeto housing 2048 on a rail 2139. Rail 2139 is optional.

A distal end, i.e., a first end, of preload release lever 2186 includesa hook 2186A that engages with and disengages from preload tab 2184T. Inthis example, hook 2186A has a flat planar surface that extends from aside surface of preload release lever 2186. The flat planar surface ofhook 2186A is configured to contact the first planar surface of preloadtab 2084T so that distal movement of preload tab 2184T causes preloadrelease lever 2186 to move distally along with preload tab 2184T.

A ramped surface extends from the end of flat planar surface of preloadrelease lever 2186 removed from the side surface of preload releaselever 2186 to a distal end of preload release lever 2186. The slope ofthe ramped surface at the distal end of preload release lever 2186 isthe opposite of the slope of the ramped surface on tab 2184T so thathook 2186A and tab 2184T can move by each other in the proximaldirection when the preload is released.

Emergency instrument release button 2082 is mounted to apply a force toa proximal end, a second end, of preload release lever 2186. In theexample of FIGS. 21B and 21C, if emergency instrument release button2082 is activated, emergency instrument release button 2082 applies apreload disengage force to the proximal end of preload release lever2186, which causes preload release lever 2186 to pivot about pivot pin2187 in a preload disengage direction, clockwise in FIGS. 20B and 20C.

The pivoting of preload release lever 2186 about pivot pin 2187 in apreload disengage direction causes hook 2186A to disengage from tab2184T of nut 2184. Consequently, motor pack return spring 2047 movesmotor pack 2046 in the proximal direction to no preload position 2032relative to instrument manipulator assembly housing 2048.

To engage the preload, controller 290 commands motor 2181 to move nut2184 proximally from either the position in FIG. 20B or the position inFIG. 20C to the position in FIG. 20A. Since tab 2184T is distal to hook2186A, as nut 2184 moves tab 2184T proximally, the ramped surface of tab2184T contacts the ramped surface of hook 2186A of preload release lever2186. As tab 2184T continues to move proximally, the ramped surface oftab 2184T pivots preload release lever 2186 until the first planersurface—the distal planar surface—clears the first planar surface ofhook 2186A, and then the torsional spring about pivot pin 2187 rotateshook 2186A in the preload engage direction so that first planar surfaceof hook 2186A and first planar surface of tab 2184T are in contact. Thisengages the preload mechanism, because now when tab 2184T moves, hook2186A moves, which in turn moves motor pack 2046.

Specifically, as shown in FIGS. 21A and 21B, when the preload mechanismis engaged and motor pack 2046 is in no preload position 2032 andcontroller 290 commands preload assembly 2080 to move motor pack 2046 tolow preload position 2033, motor 2181 moves nut 2184 in the distaldirection. Movement of nut 2184 in the distal direction causes tab 2184Tto apply a force on hook 2186A in the distal direction. The force onhook 2186A moves arm 2088 in the distal direction, which moves motorpack 2046 in the distal direction relative to instrument manipulatorhousing 2048 to low preload position 2033.

As shown in FIGS. 21B and 21C, when the preload mechanism is engaged andmotor pack 2046 is in low preload position 2033 and controller 290commands preload assembly 2080 to move motor pack 2046 to high preloadposition 2034, motor 2181 moves nut 2184 in the distal direction.Movement of nut 2184 in the distal direction causes tab 2184T to apply aforce on hook 2186A in the distal direction. The force on hook 2186Amoves arm 2088 in the distal direction, which moves motor pack 2046 inthe distal direction relative to instrument manipulator housing 2048 tohigh preload position 2034.

In the aspects illustrated in FIGS. 21A to 21C, with respect toemergency instrument release button 2082, preload release lever 2186 isa Class 1 lever because the fulcrum (pivot pin 2187) is between theeffort (the force supplied by preload release button 3082) and the load(the coupling between hook 2186A and tab 2184T). While in this example,preload release lever 2186 is implemented as a Class 1 lever, this isillustrative only and is not intended to be limiting. In other aspects,a Class 2 lever or a Class 3 lever could be used. For a Class 2 lever,the load is between the fulcrum and the effort, and for a Class 3 lever,the effort is between the fulcrum and the load.

All of the states and all of the acts in FIG. 8 can be achieved usinginstrument manipulator assembly 2040 that includes preload assembly2080. Thus, the description of FIG. 8 is not repeated for the aspects ofinstrument manipulator assembly 2040 that includes preload assembly2080. Here, controller 290 directly controls the preload, and thepreload is not dependent upon the movement of instrument manipulatorassembly 2040 by insertion mechanism 2031. Thus, the acts in FIG. 8where controller 290 moved the instrument manipulator assembly to set orreset the preload mechanism are not needed when instrument manipulatorassembly 2040 that includes preload assembly 2080 is used.

Thus, in one aspect, controller 290 maintains no preload force on motorpack 2046 of instrument manipulator assembly 2040 if sterile adapterassembly 2050 is not mounted on instrument manipulator assembly 2040.Controller issues a command directly to preload assembly 2080 toincrease the preload force on motor pack 2046 of instrument manipulatorassembly 240 from the no preload force to a first preload force aftersterile adapter assembly 2050 is mounted on instrument manipulatorassembly 2040. Controller issues another command directly to preloadassembly 2080 to increase the preload force on motor pack 2046 ofinstrument manipulator assembly 240 from the first preload force to asecond preload force after an instrument is mounted on sterile adapterassembly 2050.

In one aspect, mechanical instrument removal lockout assembly 2090 isimplemented with elements equivalent to those shown for preload assembly2080 in FIG. 21A, and so that description is not repeated for mechanicalinstrument removal lockout assembly 2090. In another aspect, assemblies2080 and 2090 are combined in a single assembly that performs both thepreload functionality and the mechanical instrument removal lockfunctionality with the two functionalities being independent of eachother.

In some of the above examples, the terms “proximal” or “proximally” areused in a general way to describe an object or element which is closerto a manipulator arm base along a kinematic chain of system movement orfarther away from a remote center of motion (or a surgical site) alongthe kinematic chain of system movement. Similarly, the terms “distal” or“distally” are used in a general way to describe an object or elementwhich is farther away from the manipulator arm base along the kinematicchain of system movement or closer to the remote center of motion (or asurgical site) along the kinematic chain of system movement.

As used herein, “first,” “second,” “third,” “fourth,” etc. areadjectives used to distinguish between different components or elements.Thus, “first,” “second,” “third,” “fourth,” etc. are not intended toimply any ordering of the components or elements.

The above description and the accompanying drawings that illustrateaspects and embodiments of the present inventions should not be taken aslimiting—the claims define the protected inventions. Various mechanical,compositional, structural, electrical, and operational changes may bemade without departing from the spirit and scope of this description andthe claims. In some instances, well-known circuits, structures, andtechniques have not been shown or described in detail to avoid obscuringthe invention.

Further, this description's terminology is not intended to limit theinvention. For example, spatially relative terms—such as “beneath”,“below”, “lower”, “above”, “upper”, “proximal”, “distal”, and thelike—may be used to describe one element's or feature's relationship toanother element or feature as illustrated in the figures. Thesespatially relative terms are intended to encompass different positions(i.e., locations) and orientations (i.e., rotational placements) of thedevice in use or operation in addition to the position and orientationshown in the figures. For example, if the device in the figures isturned over, elements described as “below” or “beneath” other elementsor features would then be “above” or “over” the other elements orfeatures. Thus, the exemplary term “below” can encompass both positionsand orientations of above and below. The device may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly. Likewise,descriptions of movement along and around various axes include variousspecial device positions and orientations.

The singular forms “a”, “an”, and “the” are intended to include theplural forms as well, unless the context indicates otherwise. The terms“comprises”, “comprising”, “includes”, and the like specify the presenceof stated features, steps, operations, elements, and/or components butdo not preclude the presence or addition of one or more other features,steps, operations, elements, components, and/or groups. Componentsdescribed as coupled may be electrically or mechanically directlycoupled, or they may be indirectly coupled via one or more intermediatecomponents.

All examples and illustrative references are non-limiting and should notbe used to limit the claims to specific implementations and embodimentsdescribed herein and their equivalents. Any headings are solely forformatting and should not be used to limit the subject matter in anyway, because text under one heading may cross reference or apply to textunder one or more headings. Finally, in view of this disclosure,particular features described in relation to one aspect or embodimentmay be applied to other disclosed aspects or embodiments of theinvention, even though not specifically shown in the drawings ordescribed in the text.

What is claimed is:
 1. A computer-assisted apparatus comprising: aninstrument manipulator assembly comprising a preload assembly; and acontroller coupled to the instrument manipulator assembly; wherein thecontroller is configured to: move the instrument manipulator assembly toa fully withdrawn position; and command the preload assembly to engage apreload.
 2. The computer-assisted apparatus of claim 1, wherein thecontroller is further configured to move the instrument manipulatorassembly to a home position after the preload is engaged.
 3. Thecomputer-assisted apparatus of claim 2, wherein: the instrumentmanipulator assembly further comprises a housing and a motor pack; themotor pack comprises one or more drive output disks; and moving theinstrument manipulator assembly to the home position while the preloadis engaged causes the one or more drive output disks to extend from adistal face of the housing.
 4. The computer-assisted apparatus of claim2, wherein the fully withdrawn position is proximal to the homeposition.
 5. The computer-assisted apparatus of claim 1, wherein movingthe instrument manipulator assembly to the fully withdrawn positionautomatically releases the preload.
 6. The computer-assisted apparatusof claim 1, wherein: the instrument manipulator assembly furthercomprises a motor pack; and moving the instrument manipulator assemblyto the fully withdrawn position automatically releases a preload forceon the motor pack.
 7. The computer-assisted apparatus of claim 1,wherein: the instrument manipulator assembly further comprises a motorpack; and engaging the preload causes the preload assembly to assert apreload force on the motor pack.
 8. The computer-assisted apparatus ofclaim 1, wherein: the instrument manipulator assembly further comprisesa motor pack; the preload assembly comprises a cam following assemblycomprising a wheel and a body; the wheel is configured to ride on apreload track; the body is rotatably coupled to a first pivot pin; thebody has a first and a second end; the second end of the body is coupledto the motor pack; and the first end of the body is coupled to thewheel.
 9. The computer-assisted apparatus of claim 8, wherein: thepreload assembly further comprises a preload engagement arm comprising afirst end and a second, the first end of the preload engagement armbeing coupled to the first pivot pin; and a rolling pin mounted in thesecond end of the preload engagement arm.
 10. The computer-assistedapparatus of claim 9, wherein the preload assembly further comprises: asecond pivot pin; a preload engage/disengage arm rotatably coupled tothe second pivot pin, the preload engage/disengage arm being couplableto and decouplable from the rolling pin; and a torsional spring mountedon the second pivot pin and coupled to the preload engage/disengage arm,the torsional spring being configured to provide a torque on the preloadengage/disengage arm to hold the preload engage/disengage arm in adisengaged position from the rolling pin.
 11. The computer-assistedapparatus of claim 10, wherein the preload assembly further comprises anelectronic actuator coupled to the preload engage/disengage arm and tothe controller, wherein when an engage command from the controller isreceived by the electronic actuator, the electronic actuator provides atorque on the preload engage/disengage arm to hold the preloadengage/disengage arm in an engaged position with respect to the rollingpin.
 12. The computer-assisted apparatus of claim 10, wherein: thepreload assembly further comprises an emergency instrument releasebutton coupled to the preload engage/disengage arm; and activating theemergency release button causes the preload to be disengage.
 13. Amethod comprising: moving, by a controller, an instrument manipulatorassembly to a fully withdrawn position; and commanding, by thecontroller, a preload assembly of the instrument manipulator assembly toengage a preload.
 14. The method of claim 13, further comprising:moving, by the controller, the instrument manipulator assembly to a homeposition after the preload is engaged.
 15. The method of claim 14,wherein moving the instrument manipulator assembly to the home positionwhile the preload is engaged causes one or more drive output disks ofthe instrument manipulator assembly to extend from a distal face of ahousing of the instrument manipulator assembly.
 16. The method of claim14, wherein the fully withdrawn position is proximal to the homeposition.
 17. The method of claim 13, wherein moving the instrumentmanipulator assembly to the fully withdrawn position automaticallyreleases the preload.
 18. The method of claim 13, wherein moving theinstrument manipulator assembly to the fully withdrawn positionautomatically releases a preload force on a motor pack of the instrumentmanipulator assembly.
 19. The method of claim 13, wherein engaging thepreload causes the preload assembly to assert a preload force on a motorpack of the instrument manipulator assembly.
 20. The method of claim 13,further comprising disengaging the preload in response to activation ofan emergency instrument release button.